Abstract
The Hitachi group has dedicated a great effort to research and development in order to meet present global environment regulations. For pulverized coal combustion, we have developed an extremely low-NOx burner (HT-NR) from our original theory of "In-Flame NOx Reduction". The second-generation burner (HT-NR2) that enhanced the effect of NOx decomposition has been applied to both Japan's domestic and overseas boilers, and has received high evaluation from all users. The latest generation burner (HT-NR3) was created and developed due to the need for high efficiency, low-NOx and easy maintenance. The HT-NR3 burners have already been put into operation in several units, worldwide. The paper will present the theory of HT-NR series and the updated results from both new installation and retrofit case.
