Numerical Investigation of Reburning Flow in a Carbon Monoxide Boiler

This study investigates the combustion and fluid flow in a carbon monoxide boiler from the Formosa Petrochemical Corporation in Taiwan, with emphasis on the effect of reburning on NOx reduction. It is found that NOx reduction occurs mainly behind the DeNOx section where recirculation is strong. A smaller reburn hole yields better NOx reduction while a larger reburn hole yields worse NOx reduction and a localized high temperature region near the reburn hole. NOx reduction is better for a lower primary/reburn fuel ratio and a higher inlet/reburn air ratio. A single-reburn-hole arrangement yields lower NOx concentration and temperature than does a three-reburn-hole arrangement.