PDF《博士学位论文公示材料》

6 个操作参数对全系统碳素消耗和第一耗指 标的影响.以鼓风温度和含氧量为自变量时碳素消耗的变化为例,其三维函数关系为非线性的,碳素 消耗降低的方向为围绕原点的弧形辐射状.固定鼓风含氧率时,鼓风温度越高,则碳素消耗越低;

固 定鼓风温度时,随着鼓风含氧率的增加碳素消耗非线性地先增后减. 富氧率-鼓风温度-第一耗 三 维系统的轮廓与碳素消耗作目标函数时相似,第一耗的最低点出现在高鼓风温度和高富氧条件下. (5) 优选出的 TGR-OBF 工艺最低碳素消耗达 289kg/t,低于普通高炉的理论最低碳素消耗水平. 综合考虑的TGR-OBF工艺焦比150kg/t, 煤比237kg/t, 碳素消耗为300kg/t, 比普通热风高炉降低125kg/t, 两种耗指标分别为 12.34 GJ/t 和11.96 GJ/t,第一耗低于普通高炉 3.29GJ/t,第二耗与普通高炉的 ―2― 数据持平.该工艺既可降低碳素消耗,又能抵消顶气脱除 CO2 的耗,系统的效率为 85%.此外, 由于大量的 CO 气体在炉内循环以及炉顶 CO2 脱除装置的有效运转,工艺的 CO2 排放量仅为

71 m3 /t, 较之传统热风高炉 CO2 减排约 90%,因为节约焦炭而降低的污染物排放也很可观. ―3― 论文摘要(英文) Taking advantages of high productivity, high PCI rate, low fuel rate, low CO2 emission, etc, the top gas recovery oxygen blast furnace (TGR-OBF) process is considered to be one of the promising ironmaking processes in future. However, after adopting high oxygen enriched blast, high PCI rate and top gas recycling system, the technical and economic indexes usually deteriorate due to the complexity of the whole systems increasing the difficulty in operation technology, and also due to the lack of unsteady simulation of the TGR-OBF systems. Furthermore, because the optimization and overall arrangement of the hot blast stove and TGR-OBF systems are not determined, the industrial operation is usually aimless and uncertain. According to investigation and survey, the thermodynamic data used in the calculation of the oxygen blast furnace process are not consistent and not satisfied to the constraint conditions of the predominance area diagram. Meanwhile, the disputes of the iron oxides reduction mechanisms are usually reported in internal and international academic journals, which makes the fundamental theory of the kinetics are not reliable in simulation of the oxygen blast furnace. In this paper, the accurate predominance area diagram and the corresponding thermodynamic data are obtained according to constraint fitting and differential thermal experiment researches. Taking the parameters of time, atmosphere and pressure into account, the mathematical simulation of the indirect reduction of the constraint step in blast furnace shaft is studied. It is found that the indirect reduction degree is linear to the reducing gas content produced in the bosh. The unsteady mathematical simulation and multi-objective optimization models are established with the hot blast stove and TGR-OBF systems are boundled as a whole research object, considering the kinetic constraint step, chemical equilibrium of the shaft gas combustion and self-consistency of physical properties of the cycled gas. The unsteady simulation of the TGR-OBF process is carried out to illustrate the change of the process parameters and technical &

economic indexes. According to researches of the fundamental theory, unsteady mathematical simulation and multi-objective optimization of the TGR-OBF process, four main results are obtained as follows: (1) When iron oxides are reduced by CO and H2, the triple phase point of the reactions is 576? C, the transition temperature of the reducibility of CO and H2 is 819? C;