Temperature measurement of molten iron in taphole of blast furnace combined temperature drop model with heat transfer model

Abstract

The molten iron temperature in the taphole of a blast furnace (BF) is an important variable which reflects the internal heat of the BF. However, there is no method to detect the temperature directly. To solve this difficulty, an approach to measure the temperature of molten iron in taphole is proposed in this paper. First, during the stable tapping period, a heat transfer model is established according to the principle of equal heat flux of the trench walls, which is used to calculate the molten iron temperature at different positions in the main pipeline according to the temperature measured by thermocouples buried in trench walls. Next, a main pipeline temperature drop model is established based on the pipe temperature drop theory. Finally, the output of heat transfer model is used as the data source for parameter identification in the temperature drop model. The least-squares method is adopted to identify the molten iron temperature in the taphole. The proposed approach was validated in a practical industrial experiment at the #2 BF in an iron making plant. The results illustrate the effectiveness and rationality of the proposed approach and provides credible temperature data for the control of the BF.