Condition Monitoring of Combustion Processes Through Flame Imaging and Kernel Principal Component Analysis

Abstract

This article presents a methodology for the diagnosis of abnormal conditions in a combustion process through flame imaging and kernel principal component analysis (KPCA). A digital imaging system is used to capture real-time flame images and radiation signals, from which flame characteristics such as flame area, brightness, non-uniformity, and oscillation frequency are quantified. These characteristics are used as the variables to establish the KPCA model of the combustion process. With the use of Hotelling's T² and Q statistics, the monitoring of abnormal conditions of the combustion process is achieved. Unlike the traditional principal component analysis (PCA) method, the KPCA method is capable of dealing with nonlinear data via nonlinear mapping, which projects the original nonlinear input space into a high-dimensional linear feature space. The effectiveness of the methodology is demonstrated by applying the approach to processing the data obtained on a 9MW_th heavy oil fired combustion test facility. Experimental results obtained show that the KPCA method outperforms the traditional PCA in discriminating between the normal and abnormal combustion conditions, even in cases where the number of training samples is limited.

Keywords:

• Combustion process
• Condition monitoring
• Digital imaging
• Fault detection
• Flame monitoring
• Hotelling's T² statistic
• KPCA
• Q statistic

ACKNOWLEDGMENTS

The authors wish to acknowledge the Research Councils UK (RCUK) for providing financial support for this research as part of The Energy Programme managed by the Engineering Physical Sciences Research Council (EPSRC, EP/F061307/1). The Energy Programme is an RCUK cross-council initiative led by the EPSRC and contributed to by ESRC, NERC, BBSRC, and STFC.