Design improvement for blackbody cavity sensor for continuous measurement of molten steel temperature

The blackbody cavity sensor formed by two coaxial tubes has been widely used in continuous temperature measurement of molten steel. However, due to the closed bottom of the inner tube, the temperature accuracy, response time and temperature measurement stability are seriously affected. It's necessary to redesign and improve sensing mechanism of the traditional design, which involves multidisciplinary knowledge, including materials, heat and flow science. This paper proposes a virtual verification-based design improvement method for blackbody cavity sensor. After redesigning the structure of the sensor, a virtual model for the sensor is established. Through real-world experiment, it is found that for the temperature measurement accuracy, the deviation between the simulation and the real-world experimental result is less than 1.5°C, and for the stability time of temperature measurement, the simulation result has a deviation from the real-world experimental result less than 15%. This verifies the accuracy of the virtual model. On this basis, model simulation for further possible optimal structures and parameters is carried out, and the influence of different nitrogen flow rates and inner tube lengths on the temperature measurement accuracy and the stability time for temperature measurement is further analyzed.