Design And Research On Temperature Field Reconstruction System Based On Acoustic Method

In industrial ironmaking,the internal temperature of the blast furnace is an important operating parameter in the monitoring and control of the blast furnace,and industrial production can be performed efficiently and safely according to the temperature.The distribution of the temperature field in the furnace is complicated.Traditional measurement methods mainly use thermocouple measurement to measure certain specific locations to realize the monitoring of the distribution of the temperature field in the furnace.The disadvantage of this method is that the measurement points are limited and the location is not variable.The reconstruction accuracy of the internal temperature field is low,and the thermocouple is easily damaged and difficult to maintain.Acoustic temperature measurement is a technique for measuring temperature using acoustic signals propagated in a gaseous medium.It is a non-contact measurement method.It has a large measurement space,a wide temperature range,and a fast response speed to enable real-time dynamic monitoring and convenient maintenance.It can better reduce the distribution of complex temperature field in the furnace.It can solve the defects of traditional thermocouple measurement methods.This article focuses on the application of acoustical temperature measurement technology in the measurement of temperature field in blast furnace,mainly to complete the following work:Firstly,the theoretical basis of temperature measurement by acoustic method is introduced,and the basic equations of temperature measurement by acoustic method in gas medium are deduced,and the intermal relationship between sound speed and temperature is analyzed.Then the principle of the measurement of the sound wave flying time is studied,and the application of the cross-correlation method in time delay estimation is analyzed.Then described the method of acoustic temperature measurement.An acoustic temperature measurement system based on STM32 processor is designed according to the basic principle of acoustic temperature measurement and practical application.The system includes acoustic wave generation circuit,power amplifier circuit,acoustic wave receiver circuit,filter and processing circuit and communication circuit.This system can generate sinusoidal sound wave signal,after the signal is received,it will be filtered and denoised,and then it will be amplified and adjusted by the programmable amplifier under the appropriate coefficient and then transmitted to the A/D converter of the micro-control unit and saved in memory,the data is finally uploaded to the upper computer through the communication circuit for processing analysis.The reconstruction algorithm of temperature field is studied,and two reconstruction methods of least square method and regularization algorithm are analyzed.The method of computer simulation was used to establish unimodal symmetric model temperature field and unimodal deflection model temperature field.The temperature field reconstruction program was written according to two algorithms respectively,and the temperature field was reconstructed after processing the simulation data,and then compared with the model temperature field.The results show that both algorithms can complete the reconstruction of the temperature field within the allowable error range,and verify the feasibility of the acoustic temperature measurement system.Based on the above studies,the acoustic temperature measurement systen was verified experimentally.The experiments were carried out on the non-heat source temperature field and the single-peak temperature field.The experimental results can well reflect the temperature distribution characteristics of the temperature field.The measurement system based on acoustic temperature measurement is feasible.