Research On Temperature Online Detection And Temperature Compensation Use The Method Of Double Colorimetric Of AOD Furnace

In AOD furnace smelting, adjusting smelting temperature plays a very important role in ensuring the steelmaking process and product quality. The purpose of this study is researching temperature measurement theory that meets practical production needs and building a set of temperature on-line monitoring system.AOD furnace temperature reflects the chemical variation in the furnace. Thus, obtaining the furnace temperature can control the reaction of AOD furnace and achieve the desired metallurgical objectives; secondly the lining life of AOD furnace is limited and excessively high temperature will easily damage the lining. In smelting, if the smelting temperature is controlled and the damage of the lining is reduced, the lining life will be extended and production costs will be saved. On the other hand, when the smelting temperature is in an effective range, it can prevent splashing accidents and ensure safety in production.In the paper, we choose double colorimetric infrared thermometry as the optimum online temperature measurement. Theend point of the gun is selected as a temperature probe to obtain the furnace two channel of radiation signal.then, based on the conversion between the intensity of two-channel optical signal and the actual temperature, their mathematical model is established; designing the optical path of temperature measurement system and circuit hardware part to amplify, convert, transmit and process the optical signal collected from the furnace, the communication with PC was realized via wireless transmission module and the PC for data management and temperature display was completed by VB human-computer interaction; cooling subsystem ensure that theoperating temperature of the thermometer is normal.A large number of industrial field data shows that there are some errors between the thermometer temperature and the actual temperature in smelting furnace. The study found that changes in the mixed gas blown into the bottom gun interference initial acquisition of the optical signal. For the error, temperature compensation model was established to improve the accuracy of the online thermometer. Here, according to the blowing ratio, the variation of the molten iron temperature field and the blackbody cavity theory of bottom blowing oxygen gun mixed gas in the process of smelting, temperature compensation model was established. By least-squares curve fitting for infrared temperature measurement system for field calibration, we can ensure that the system obtain reliable experimental data.Practice has proved that the infrared temperature measurement system used in this paperachieved AOD furnace smelting temperature on-line continuous monitoring and improved the measurement accuracy of the system.