Time Delay Estimation for Boiler Tube Leak Sound Propagation

The interference of strong background noise and reflected by the surface of wall and tube rows in industrial boiler furnace,renders the generalized cross-correlation(GCC) peaks of tube leak sound pressure signals received by sensors array ambiguous,even the stable peak couldn’t be searched at all,which leads to leak position may fail to accurately be fixed.The 600MW supercritical boiler model was established,the leakage source propagation process of reflection and attenuation in boiler furnace was simulated by enhanced acoustic simulator for engineers(EASE),the approximate signal to noise ratio(SNR) was obtained through it;The reverberation time was calculated with the modified Sabine and squared impulse response integration method by the simulation.The time delay estimation algorithm: phase transformation(PHAT),maximum likelihood(ML),phase transform for noise(PTN,derived from PHAT) and SWITCH were evaluated and results revealed the superiority of SWITCH and PTN methods in reverberant and noisy boiler background.Although SWITCH is outperformed by PTN slightly,but the prior knowledge of reverberant energy to direct energy ratio and frequencies onset detection is required in PTN method.