| Blast furnaces with longevity, high efficiency and low cost are always pursued bysteel companies. With the upsizing and increment of production intensity, more andmore attentions are paid to the service life of blast furnace. The refractory erosions ofhearth and bottom restrict the longevity of blast furnace, and accidents caused byburnout of hearth occurred occasionally. Therefore, it is of practical significance todevelop a software to monitor the hearth and bottom erosions of blast furnace in realtime.To meet the actual need of burst furnace operators, this paper has successfullydeveloped the on-line monitoring software system for the hearth bottom corrosion ofblast furnace, based on numerical heat transfer and computer graphics displaytechnology. The software system consist of data communication, data acquisition ofthermocouple temperature, on-line computation of hearth and bottom corrosion, andgraphic display, etc. It can calculate the temperature distribution of hearth and bottomwith the measured temperatures of thermocouples, and thus predict the corrosion ofhearth and bottom.The main innovations are listed as below:(1)The non-linear relationship between the thermal conductivity of refractory andtemperature has been taken into account in the model calculation. The functions areobtained by the methods of Lagrange’s interpolation.(2) The finite difference method is used for numerical solution of temperature field,and the harmonic formula is adopted for the thermal conductivity at the interface ofadjacent computational cells, which significantly reduce the programming workload.(3) The bad and singular points in the measured temperatures from blast furnacethermocouples are preprocessed with the method of algorithm combined with manualcorrection before the model calculation, and the temperature inputs for numericalerosion-prediction model is secured to be correct and complete.(4) The isothermal curve of1150℃is the important indicator for the erosionsituation of hearth and bottom. The real erosion curve is approached by contrasting thecalculated temperatures with measured counterparts and dynamically vertically orhorizontally adjusting corresponding control points of the erosion curve.(5) The graphic display of the temperature distribution in the hearth and bottom is realized by creating point sprite through DirectX applications.The current system has been successfully applied to No.4blast furnace ofiron-plant of Wuhan Iron and Steel Corporation and provided erosion information ofhearth and bottom for blast furnace operators in real time. By comparing the calculatedtemperature with the actual measured temperatures in the hearth and bottom of blastfurnace, the average error and average relative error are equal to5.9℃and1.58%,respectively. These errors can be tolerated in the engineering.In summary, the on-line monitoring system for the hearth bottom corrosion of blastfurnace is reliable, the prediction results is reasonably accurate, which is expected to bepromoted and used at other blast furnaces. |
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