Heat-rate and NO_x optimization in coal boilers using an advanced in-furnace monitoring system

摘要

This paper will present the OPTICOM monitoring technology, which has been extensively applied in several Spanish and Portuguese coal-fired power stations. This novel monitoring system allows to measure local gas concentration levels (O_2, CO, NO_x, SO_2, CO_2) in any interior point of the furnace. OPTICOM provides significant and direct information about the real development of the combustion process, guiding the operator to obtain the most adequate tuning of any individual burner and, therefore, bringing about the overall optimization of the boiler. This new tool has been demonstrated as a critical step forward respecting the demands of power plant operators, for which up to now combustion was almost a "black box" process. Application of this new in-furnace monitoring system to pulverized coal boilers has enabled heat rate improvements over 1%, coupled with NO_x emission reductions up to a 30%. This significant performance upgrading has been achieved through targeted boiler tuning, aimed to correct combustion malfunctions detected by the OPTICOM monitoring approach.