Study On High Temperature Measurement In Scrap Copper Furnace

Copper has lots of excellent characteristics and is widely used in manufacturer and our daily life. Scrap copper plays an important role in copper resources and is widely distributed; compared with traditional copper ore, scrap copper smelting consumes less energy but is much more complicated. Shaft furnace smelting is a new semi-batch scrap copper smelting technology. However, its internal temperature measurement, the basis of its process diagnosis and control, meets some difficulties.In order to solve this problem, we studied the high temperature measurement in scrap copper furnace and innovatively proposed an indirect measurement method that we used thermocouple to get the temperature inside furnace wall and then calculated internal wall surface temperature. In this thesis, the following sections are introduced:1. After analyzing the requirement of copper furnace temperature measurement and control, we built the nonlinear transient heat transfer model of the wall according to its physical structure. Then finite element method (FEM) was introduced to solve and understand model steady temperature field problem, which helped to verify the effectiveness of the model.2. Temperature measurement synthetically optimal localization criterion was proposed to find an optimal thermocouple measurement location which influences measurement performance and temperature identification precision. Based on optimum experimental design theory and thermocouple's characteristics, temperature measurement criterion was presented. With the help of COMSOL and MATLAB software, we designed the solving process and found out the optimal measurement position in the scrap copper furnace wall.3. After studying the ill-posed characteristics of inverse heat transfer problem (IHTP), we divided furnace wall into direct region and inverse region, chose orthogonal Gram polynomial theory to smooth and filter the thermocouple signal, used FEM to get heat flux on internal boundary of direct region, finally calculate internal surface temperature with method of line, which realized indirect furnace temperature measurement. Experiments showed that our method conquered the ill-posed characteristic of IHTP and worked efficiently.In the end, future work is pointed out and research is still ongoing.