Oxygen analisers clean up power plant

Citation

(2001), "Oxygen analisers clean up power plant", Sensor Review, Vol. 21 No. 1. https://doi.org/10.1108/sr.2001.08721aab.008

Oxygen analisers clean up power plant

Oxygen analisers clean up power plant

Keywords: Oxygen, Emissions

Managers of a major power plant approached AC Controls of Charlotte, North Carolina, to get analysers to monitor the oxygen level in boiler combustion fuel gases. The information would guide plant operators in adjusting fuel/air ratios for maximum combustion efficiency and in reducing nitrogen oxide emissions. Combustion tests had found that stratification of different mixtures exists in the large flue gas ducts, requiring 16 analysers to average out the variations in flue gas. AC Controls is incorporating World Class 3000 oxygen analysers made by Rosemount Analytical Inc.'s process analytical division in Orrville, Ohio, to do the job.

The World Class 3000 contains a heat sensing cell made of zirconium oxide that becomes an electrolytic conductor when there is a difference between the oxygen level in the flue gas and the reference standard of ambient air, which is 20.95 percent. When there is a difference, the cell generates a small voltage that is received by porous platinum electrodes deposited on both sides of the cell. Microprocessor based electronics condition and amplify this small signal, and send it into an automatic control system that modulates the main burner fans to control oxygen value.

Rosemount designed the oxygen analyser so that it can be diagnosed and calibrated from the control room while providing readings with 0.75 percent accuracy.