Research And Apply On Demodulation Methods Of Distributed Fiber Temperature Measurement Oriented To Hot Blast Stove

Hot air stove has a vital role in the field of industrial iron-making,therefore,temperature measurement and monitoring of hot air furnace is particularly necessary.Traditional temperature measurement methods are not only costly,inconvenient,but also have other shortcomings.Thus,this paper proposed a new method named distributed fiber temperature measurement to measure the temperature of hot air stove.Distributed optical fiber temperature measurement technology is a new high-tech technology for real-time measurement of space temperature field.The basis of its development are OTDR and Raman scattering temperature principle.Because of the emphasis on the signal demodulation of this technology,this paper focused on the multi-demodulation methods of distributed fiber temperature measurement and the temperature characteristics of hot air furnace,innovatively proposes a double terminal and double channel demodulation method(DTDC).In this paper,the application of distributed optical fiber temperature measurement technology based on DTDC demodulation method in hot air furnace was introduced in three parts.Firstly,based on the hot air stove,the research background and significance of the topic,the research status of hot air furnace temperature measurement and distributed fiber temperature measurement were introduced,and it was necessary to raise a new type of demodulation.Secondly,in terms of the development of hot air furnace temperature measurement,the existing demodulation method and other theoretical parts,this paper put forward the corresponding solutions for raised problems,and the overall structure of the system design was obtained,it was mainly divided into two parts,including hardware and software.The hardware module consisted of light source,sensor fiber,optical switch,WDM,photoelectric detector and the processing module of FPGA plus DSP.The software module contained the program design of data collection,denoising and demodulation,besides,it also contained environment configuration,program settings connection between hardware and host computer.Finally,the performance of the temperature measurement system which is combined by the software and hardware was tested.Different demodulation methods were firstly compared in laboratory,and the sequel showed that DTDC demodulation method was better than others,then,the temperature accuracy and system resolution were tested,the results met the industrial site requirements of hot blast furnace.This paper was devoted to applying the latest research results of distributed optical fiber temperature measurement to a steel hot air furnace temperature measurement system,and the system temperature measurement accuracy and spatial resolution were tested.The test results showed that the system was easy to install,and measurable temperature ranged between-10~200?,the maximum temperature error was inferior to0.5?,positioning accuracy was 0.5m.In conclusion,this system met the requirements.This research has a good theoretical significance and application prospect in the field of industrial temperature measurement.