An experimental comparison of the airflow characteristics of four-walls tangential firing and four-corners tangential firing

A new kind of tangential firing four-walls tangential firing (FWT)-has been gradually adopted in large utility boilers, particularly supercritical boilers. It is necessary to determine the airflow characteristics of this new method. In this study, we use a cold modeling experimental device in laboratory based on the prototype of one 660 MW power supercritical boiler with PINT. From results of particle tracing and particle dynamic analyzer measurements, we study the airflow characteristics in the furnace. We also compare the observed airflow characteristics with those of traditional four-corners tangential firing (FCT). We are able to discern differences in airflow characteristics between PINT and FCT. We find that for PINT, the rigidity of the jets is not only influenced by the rotating airflows, but also by the adjacent upstream jets. Furthermore, the airflow velocities close to the wall of FWT are significantly higher than those of FCT and the directions of the airflow are almost all oriented toward the wall. (C) 2014 Elsevier Inc. All rights reserved.