Optimized Design Of The High Temperature Furnace Heater Structure

High-temperature fixed point is the international temperature metrological field major breakthrough and research focus in the last 10 years. However, the most basic condition of carrying out high-temperature fixed point research is high-temperature furnace with a certain performance requirements. ThermoGauge high temperature Blackbody furnace has many advantages,but its drawback is its heater (referred to the tube) axial temperature profile gradient is too large, which brings the uncertainty to the study of fixed-points. The paper uses the combination of the experimental study and finite element thermal simulation to design different tube's structures for the requirements of different high-temperature fixed points, which Co-C is 1324℃, Pt-C is 1738℃and Re-C is 2474℃.Therefore, the main research topics are:(1) The study of TG furnace tube axial temperature profiles precise measurement method. When temperature is 1300℃,using thermocouple contact method to measure axial temperature profile gradient of the tube. Innovative use the radiation thermometry (mobile blackbody cavity method) to obtain axial temperature profile gradient of the tube when the temperature is 1700℃or 2500℃。(2) On the methods of the tube structure improvement, using software simulation and experimental methods to improve the structure of the tube when the temperature is 1300℃or 1700℃. Use the PRO/E to design tubes of a variety of structures (including different width and depth of cutting tube) and get axial temperature distribution of a variety of structures'tubes by ANSYS WorkBench to analysis furnace-models with tubes of a variety of structures. Compare different curves of axial temperature distribution to determine the optimal structure of the tube and experiments are used to verify temperature profile gradient greatly improved. When the temperature is 2500℃, in this paper axial temperature profiles of the existing tubes are measured and compared to analysis and design the optimal structure of tube. Similarly, experiments are used to verify temperature profile gradient of the optimal tube greatly improved when the temperature is 2500℃so that it can meet the requirements of high temperature fixed points.