Ash fouling monitoring based on acoustic pyrometry in boiler furnaces

Online Time-Resolved Reconstruction Method for Acoustic Tomography System

“…In addition to these applications, acoustic tomography also gains a great deal of interest in atmospheric imaging to monitor the temperature and wind velocity distributions of air. Reported research on atmospheric imaging based on acoustic tomography includes the atmosphere vertical temperature structure monitoring using acoustic waves from powerful explosions on the ground [14,15], the horizontal temperature and wind velocity field monitoring of the near surface atmosphere [16,17], the indoor climate monitoring system [18][19][20][21], and the furnace or boiler temperature field monitoring system [22][23][24].…”

“…This used 7 acoustic transceivers operating at 1800 Hz to cover a 5.929 by 5.313 m sensing area, and 13 TOF measurements were used for reconstruction. The North China Electric Power University developed an acoustic tomography system for the online monitoring of the coal-fired boiler [24] and Ash fouling [23]. Their transducer array consisted of 4 loudspeakers and 8 microphones whose frequency swept from 500 Hz to 8000 Hz over a duration of 0.1 seconds.…”

“…For simplicity, in some applications when the acoustic tomographic system is used in near surface atmosphere [1,[17][18][19]54], acoustic propagations between the transducer pairs are approximated as straight paths. However, in some situations, like the combustion process in furnace environment [23,24], the gradient of the temperature field can be relatively large, and the sound speed distribution is highly heterogeneous. The corresponding ray path will be curved around the heated area due to the refraction effect, and the commonly used straight ray model may cause large reconstruction error.…”

Online Ash Fouling Prediction for Boiler Heating Surfaces based on Wavelet Analysis and Support Vector Regression

“…The geometric pixel segmentation and regularization algorithm are used to reconstruct the two-dimensional temperature field [13]. Acoustic pyrometry technology is used to monitor the temperature change of flue gas on the local heating surface in the boiler furnace, and a new cleaning factor is defined to characterize the shift in the ash fouling degree [14]. However, acoustic pyrometry technology has its limitations: it can only measure the temperature change of the local heating surface; most of the heating surface is unmeasurable; and additional acoustic sensors are required.…”

An Optimization Study on Soot-Blowing of Air Preheaters in Coal-Fired Power Plant Boilers

“…It can be accomplished by using particular power plant instrumentation and online computations or a combination of both approaches. The particular power plant instrumentation, such as heat flux meters [16,17] and acoustic pyrometry [18], can easily show the status of the furnace's heat absorption by providing continuous signals, while inducing a meaningful increase in cost of installation, maintenance, and the sensor. The fuzzy models and artificial neural network are well applied in the monitoring of ash fouling of boilers [7,[19][20][21], but it is difficult for real time monitoring because of great sum of calculations.…”