In this study, the relationship between the visual information gathered from the flame images and the excess air factor 2 in coal burners is investigated. In conventional coal burners the excess air factor 2. can be o...In this study, the relationship between the visual information gathered from the flame images and the excess air factor 2 in coal burners is investigated. In conventional coal burners the excess air factor 2. can be obtained using very expensive air measurement instruments. The proposed method to predict ） for a specific time in the coal burners consists of three distinct and consecutive stages; a） online flame images acquisition using a CCD camera, b） extrac- tion meaningful information （flame intensity and bright- ness）from flame images, and c） learning these information （image features） with ANNs and estimate 2. Six different feature extraction methods have been used： CDF of Blue Channel, Co-Occurrence Matrix, L-Frobenius Norms, Radiant Energy Signal （RES）, PCA and Wavelet. When compared prediction results, it has seen that the use of co- occurrence matrix with ANNs has the best performance （RMSE = 0.07） in terms of accuracy. The results show that the proposed predicting system using flame images can be preferred instead of using expensive devices to measure excess air factor in during combustion.展开更多
In a gas/particle two-phase test facility, a three-component particle-dynamics anemometer was used to measure the characteristics of gas/particle two-phase flows in a 29 megawatt (MW) pulverized coal industrial boiler...In a gas/particle two-phase test facility, a three-component particle-dynamics anemometer was used to measure the characteristics of gas/particle two-phase flows in a 29 megawatt (MW) pulverized coal industrial boiler equipped with a new type of swirling pulverized coal burner. The distributions of three-dimensional gas/particle velocity, particle volume flux, and particle size distribution were measured under different working conditions. The mean axial velocity and the particle volume flux in the central region of the burner outlet were found to be negative. This indicated that a central recirculation zone was formed in the center of the burner. In the central recirculation zone, the absolute value of the mean axial velocity and the particle volume flux increased when the external secondary air volume increased. The size of the central reflux zone remained stable when the air volume ratio changed. Along the direction of the jet, the peak value formed by the tertiary air gradually moved toward the center of the burner. This tertiary air was mixed with the peak value formed by the air in the adiabatic combustion chamber after the cross-section of x/d = 0.7. Large particles were concentrated near the wall area, and the particle size in the recirculation zone was small.展开更多
基金supported by The Scientific and Technological Research Council of Turkey(TUBITAK,Project number:114M116)and MIMSAN AS
文摘In this study, the relationship between the visual information gathered from the flame images and the excess air factor 2 in coal burners is investigated. In conventional coal burners the excess air factor 2. can be obtained using very expensive air measurement instruments. The proposed method to predict ） for a specific time in the coal burners consists of three distinct and consecutive stages; a） online flame images acquisition using a CCD camera, b） extrac- tion meaningful information （flame intensity and bright- ness）from flame images, and c） learning these information （image features） with ANNs and estimate 2. Six different feature extraction methods have been used： CDF of Blue Channel, Co-Occurrence Matrix, L-Frobenius Norms, Radiant Energy Signal （RES）, PCA and Wavelet. When compared prediction results, it has seen that the use of co- occurrence matrix with ANNs has the best performance （RMSE = 0.07） in terms of accuracy. The results show that the proposed predicting system using flame images can be preferred instead of using expensive devices to measure excess air factor in during combustion.
基金This work was supported by National Key Research and Development Program of China(Grant No.2017YF C0212500).
文摘In a gas/particle two-phase test facility, a three-component particle-dynamics anemometer was used to measure the characteristics of gas/particle two-phase flows in a 29 megawatt (MW) pulverized coal industrial boiler equipped with a new type of swirling pulverized coal burner. The distributions of three-dimensional gas/particle velocity, particle volume flux, and particle size distribution were measured under different working conditions. The mean axial velocity and the particle volume flux in the central region of the burner outlet were found to be negative. This indicated that a central recirculation zone was formed in the center of the burner. In the central recirculation zone, the absolute value of the mean axial velocity and the particle volume flux increased when the external secondary air volume increased. The size of the central reflux zone remained stable when the air volume ratio changed. Along the direction of the jet, the peak value formed by the tertiary air gradually moved toward the center of the burner. This tertiary air was mixed with the peak value formed by the air in the adiabatic combustion chamber after the cross-section of x/d = 0.7. Large particles were concentrated near the wall area, and the particle size in the recirculation zone was small.
