Pulverized coal combustion application of laser-based temperature sensing system using computed tomography - Tunable diode laser absorption spectroscopy (CT-TDLAS)

The investigation of combustion phenomena in pulverized coal flames is significant for combustion optimization related to energy conservation and emission reduction. Real-time two dimensional (2D) temperature and concentration distributions play an important role for combustion analysis. The non-contact and fast response 2D temperature and concentration distribution measurement method was developed in this study. The method is based on a combination of computed tomography (CT) and tunable diode laser absorption spectroscopy (TDLAS). The accuracy evaluation of developed 32-path CT-TDLAS demonstrated its feasibility of 2D temperature measurement. 32-path CT-TDLAS was applied to CH4 and 5 kg/h coal combustion fields for 2D temperature measurement. The time-series 2D temperature distribution in coal combustion furnace was measured using 32-path CT-TDLAS measurement cell with kHz time resolution. The transient temperature field of combustion flame directly reflects the combustion mode and combustion stability. The measurement results demonstrate its applicability of CT-TDLAS to various types of combustor, especially the combustion fields with coal and ash particles. CT-TDLAS method with kHz response time enables the real-time 2D temperature measurement to be applicable for combustion analysis.