Combustion Engineering, Inc.

Abb Inc.

Abb Research Ltd.

Paul H Chase

James M Niziolek

Terry M Grayson

Gregory F Rossano

Hui Zhang

Donald J Kwapien

Troxell K Snyder

A signal processing technique that allows the flame signal from a first source of flame and the flame signal from a second source of flame to be discriminated from each other when only both the first and second flame signals are viewed by the same flame scanner. The signal from the flame scanner is processed to enhance one or more of the attributes associated with the first flame and is simultaneously processed to enhance one or more attributes associated with the second flame.

Signal processing technique for improved flame scanner discrimination

There is described a method and apparatus for controlling the combustion by-product formation rate in at least one burner of a fossil fuel fired power plant. The burner has an associated flame scanner which is focused on a small area of the burner flame to obtain an image signal of the flame. A flame signal that represents properties of temporal combustion in the visible light spectrum of the burner is generated from the image signal. Combustion turbulence at the burner is analyzed from the flame signal by a dynamic invariant that has a relationship to the combustion by-product values and different combustion by-product levels at the burner and the combustion turbulence is correlated to the combustion by-product formation rate at the burner. The method and apparatus can also be used to correlated the combustion turbulence at a multiplicity of burners to the associated combustion by-product formation rate.

Combustion emission estimation with flame sensing system

A flame scanner for effecting therewith individual burner flame discrimination in multi-fossil fuel fired steam generators. The subject flame scanner is based on the use therein of a silicon carbide photodiode that is operative for converting into a photocurrent ultraviolet light, which impinges upon the silicon carbide photodiode after passing through a focusing lens.

Silicon carbide photodiode based flame scanner

Fuel and oxidant feed rates into a gasifier 202 are regulated by monitoring overall output 14 and comparing with a pre-selected setpoint valve 10. An overall load demand signal 50, responsive to this comparision is generated and used as an input to control 102 oxidant feed rate. The heating value of the product gas is measured 76 and used to control 64 overall fuel feed rate to the gasifier 202. For a two stage slagging gasifier, the present invention controls 114 fuel feed rate to the slagging stage 210 responsive to the measured slagging stage reaction temperature 128.

Method and apparatus for controlling a gasifier

A flame scanner has a sensing circuit (10) utilizing a photosensitive device (12) for monitoring and a logic circuit (20) which includes a flame detection circuit (22) and a fault detection circuit (24). The photosensitive device produces a current signal (13) indicative of the intensity of the flame. The current signal is fed to a logarithmic amplifier (14) and converted to a voltage signal (15). The voltage signal (15) powers an LED (18) with its output (4) impinging on the photosensitive device (12). The voltage signal (15) is also transmitted to the flame detection circuit and the fault detection circuit for simultaneous and independent processing. The flame detection circuit continuously processes the signal to determine if a stable flame is present, while the fault detection circuit continuously monitors the integrity of the photosensitive device and its associated sensing circuitry.

Fault detection in a flame scanner

An apparatus is disclosed for realizing analog signal filters with very long time constants. In order to avoid the losses inherent in conventional energy-storage devices such as capacitors and inductors, an analog signal is converted into digital form for storage, thereby eliminating losses, and the digital quantity is continuously converted back to analog form for use in the analog circuit.

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East Granby, CT, United States of America

Paul H Chase