Online adjustment of Furnace Exit Gas Temperature field using advanced infrared pyrometry: Case study of a 1500 MWth utility boiler

Abstract

The Furnace Exit Gas Temperature (FEGT) is a key parameter of the combustion process in utility boilers that needs to be accurately monitored, especially in order to increase their load- and fuel-flexibility. However, neither the average FEGT nor its spatial distribution over the boiler cross section can be measured using standard equipment. Advanced pyrometry provides an accurate and efficient way to monitor the FEGT: by combining the signals from several pyrometers installed around the boiler, the FEGT 2D field can be reconstructed. In this paper, we show the results of a measurement campaign carried out on a 1500 MWth boiler using a system comprising 9 infrared pyrometers. Thanks to online adjustments of the combustion air distribution, the FEGT peak initially observed has been reduced by approximately 100oC, and the flame has been recentered.

Keywords

• Boiler
• Furnace exit gas temperature (FEGT)
• infrared pyrometry
• Load and fuel flexibilisation
• Hot spots
• Tube failures