44 An Online Monitoring Technology for Visualization of 3-D High Temperature Field in a Tubular Furnace

This paper presents a real-time monitoring system with visualization of three-dimensional (3-D) temperature reconstruction based on image processing technology in an experimental tubular furnace in Luoyang Ruichang Petrochemical Equipment Co. Ltd. In this system, a radiative image-formation model was adopted to establish the relationship between the radiation images and the 3-D temperature distribution inside a high temperature industrial system, and a modified Tikhonov regularization method was used to reconstruct the 3-D temperature distribution from the 2-D temperature images transformed from color images. The temperature measured by the present system at three locations, especially on the tube skin, agree well with those by thermocouples in the whole experiment process. The relative errors are almost less than 5%. The changing burner status experiment testifies this system can accurately and visualized on-line detect distribution of 3-D temperature and furnace tube skin temperature during different operating modes, for example different fuel component, different air-fuel ratioes and different burner heating capacity. By comprehensive analysis and diagnosis, this system can provide optimize regulating instruction information of optimally input air-fuel ratio for burners. Furthermore, the fast and real time response to the fire in the furnace can be utilized to provide a warning for fire extinguishing in the present system. And it supplies a new-style modern detection means for tubular furnace safety and economic operation.