Research On Acoustic Method Boiler Flame Temperature Measurement System In Thermal Power Plant

For the safe and economic operation of the boiler,mastering the real-time temperature of the flame is the first and most important step in solving the problem.Acoustic temperature measurement method is a new temperature measurement method,which has many advantages such as rapid temperature measurement and real-time continuous measurement.And it is also more convenient in terms of maintenance of the entire system.Based on the theory of acoustic waves and thermodynamics,this paper deduces the relationship between the propagation speed of acoustic waves and the temperature of the medium in detail.It briefly introduces several commonly used methods of measuring the time of flight of sound waves,and discusses the selection of sound source signals.The hardware system of the whole temperature measurement by acoustic method is designed,and each part is introduced in detail.In addition,the data acquisition link of this system uses data acquisition card,and uses LabVIEW software as the design platform.This paper uses a high-power chip as one of the innovations to ensure that the sound signal in propagation is large enough so that it can be received by the microphone instead of being overwhelmed by noise.The system is also equipped with a cooling link to protect the measuring device.Acoustic temperature field reconstruction is an ill-posed ill-conditioned inverse problem,which is very sensitive to noise changes during time-of-flight measurement.Therefore,when measuring sound wave time-of-flight,it is particularly important to use sound noise time-of-flight measurement algorithms.This article introduces in detail Classical cross-correlation algorithm and derived the relevant formula.In order to further improve the noise immunity of the system,on the basis of the cross-correlation algorithm,the second innovation of this paper is introduced: the most widely used "spectral subtraction" in the speech enhancement method.This method performs the time of flight of the sound wave in this system.During the measurement,the noise signal mixed in the sound propagation signal can be reduced.The value of the variables required for the experiment was determined by the method of experimental verification.The temperature field reconstruction process was carried out under laboratory conditions.Through the reconstruction analysis of the temperature field before and after heating,Verifies the feasibility and practicability of the acoustic temperature measurement system designed in this paper.