Stabilization method for hot metal temperature in operation change of blast furnace

In blast furnace operation, the hot metal temperature is influenced by seve ral operating factors, such as blast temperature, bias? moisture and pulver ized coal injection volume, in the case when an operating factor is changed intentionally in stepwise, one or more of the other operating factors are changed to compensate for the change so as to minimize the hot metal temper ature deviation, Conventionally, in actual operation, the operating factors are changed in a trial-and-error fashion. This paper studies the operation planning method for a blast furnace which compensates for the hot metal te mperature deviation accompanying a stepwise operation change with another s tepwise operation change. First of all, a dynamic simulator for the blast f urnace process is explained. Then the step responses of the hot metal tempe rature to several operation changes are analyzed. Next, switching operation s of coke by PC operation and coke by blast temperature are planned. This i s done using the simulated results to minimize lire evaluation function whi ch is defined as the integral of the square deviation of hot metal temperat ure. Satisfactory blast furnace operations are achieved based on this plan. Moreover, the unimodality of the evaluation function for such a switching operation of blast furnace is shown. The unimodal property means that the p roposed operation planing method is applicable for construction of the furn ace operation guidance system.