Acoustic Temperature Field Reconstruction System And Optimization Of Transceiver Layout

Acoustic temperature field reconstruction technology is a new non-contact temperature detection technology,which has a broad application prospect in the fields of ensuring the efficient and stable operation of industrial furnace system,improving the quality of grain storage,remote monitoring of atmospheric parameters and monitoring of temperature distribution of submarine hot spring.When using acoustic method to reconstruct the temperature field,a certain number of acoustic transceivers need to be arranged around the tested area,and the acoustic propagation path covering the tested area is formed between the transceivers.Therefore,when the number of transceivers is fixed,the distribution of transceivers becomes very important.In order to make the temperature field reconstruction system of acoustic method adapt to all kinds of temperature distribution better,this paper proposes a new method of transceiver location optimization,which takes the minimum reconstruction error of uniform temperature field as the objective function and particle swarm optimization as the optimization method.By using this method,eight transceiver positions around the square area are optimized.The simulation results of temperature field reconstruction of five typical models,such as four peak asymmetry,show that compared with the commonly used uniform symmetrical layout,the reconstruction error of optimized layout is smaller,and the reconstructed image can better reflect the temperature distribution in the tested area.This paper also presents a quantitative index "equivalent grid number" to evaluate the coverage of sound lines to the tested area.The "equivalent grid number" is used to explain the reason why the optimal distribution can reduce the reconstruction error.By using the optimized layout and 8-channel acoustic reconstruction system,the single peak bias temperature field formed by the electric heater is reconstructed.The reconstruction results further verify the effectiveness and practicability of the proposed method.This paper also studies the calibration method of the acoustic temperature field reconstruction system.From the aspects of the propagation characteristics of the sound wave,the theoretical path and the actual path of the sound wave propagation,the reasons for the large deviation between the theoretical value of the sound wave flight time and the measured value are analyzed.In order to overcome the adverse effect of this deviation on the reconstruction of temperature field,a two-step system calibration scheme is proposed.Firstly,the time of flight of the sound wave is calibrated by comparing the length of the forward and inverse path with the length of the theoretical path,and then the path of the sound wave is classified.The paths of different types are calibrated twice by different correction factor formulas.The validity of the calibration scheme is verified by comparing the temperature of each path calculated from the flight time of each path before and after calibration.