Continuous real time heating value (BTU)/Coal flow balancing meter

Abstract

A method and an apparatus for continuous real time heating value / coal flow balancing of coal from a coal feeder to a burner. The apparatus includes a dual-energy Gamma Attenuation (DGA) / multi-energy Gamma Attenuation (MGA) device for measuring coal quality at a specific location between the coal silo and the mill in a coal fired plant in order to control the individual burner stoichiometries according to the measured coal quality. By strategically placing the DGA / MGA device, continuous accurate real-time coal quality information is accomplished for making individual adjustments in order to improve stoichiometry to optimize performance of the system.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] Not Applicable STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable BACKGROUND OF THE INVENTION [0003] 1. Field of Invention [0004] The present invention relates to the use of nuclear response measurements of fuel flow and fuel quality combined with a process control system for optimization of air and coal stoichiometry at each burner in a coal fired boiler. [0005] 2. Description of the Related Art [0006] In the field of coal fired boilers used especially by utility companies and industrial boiler operators, it is well known that increasingly stringent emissions limits continue to apply pressure to reduce NOx emissions from coal fired boilers. Years of investigation by utilities, boiler suppliers, and controls suppliers have determined that stoichiometries local to the burners must be maintained to achieve very low NOx emissions without negatively effecting combustion efficiency or boiler performance. Co...

AI Technical Summary

Benefits of technology

[0013] The present invention is a method and an apparatus for continuous real time heating value / coal flow balancing of coal from a coal feeder to a burner. The apparatus includes a dual-energy Gamma Attenuation (DGA) / multi-energy Gamma Attenuation (MGA) device for measuring coal quality at a specific location (i.e., on the coal feeder tube between the coal silo and the mill) in a coal fired plant in order to control the parameters of the plant according to the measured coal quality. By strategically placing the DGA / MGA device, continuous accurate real-time coal quality information is accomplished for making individual adjustments in order to improve stoichiometry to optimize performance of the system.

Problems solved by technology

Common barriers to lower NOx emissions include poor coal and air distribution which may also lead to high unburned carbon, high COx, boiler slagging, and oxygen and / or steam temperature imbalances.

Deviations from the design air / fuel balance at individual burners results in burners operating at a fuel lean or fuel rich condition.

Many coal fired boilers with poor air / fuel distribution experience problems such as: emission problems; increased unburned carbon in fly ash; distorted oxygen profile at the boiler outlet; uneven steam temperature profiles; flame impingement; increased slagging; and water wall heat waste.

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