Development of a Dry Low NOx Combustor

Abstract

Controls for emissions of oxides of nitrogen were first required for gas turbines by the Los Angeles County Air Pollution Control District (LAAPCD) and the San Diego Air Pollution Control District (SDAPCD) in the early 1970’s. To achieve the necessary control, water was injected into the combustor flame zone to reduce flame temperature. The consequent reduction in NOx amounted to about forty percent when half as much water as fuel was injected into the reaction zone. The emissions level achieved was approximately 75 ppmvd (parts per million by volume dry) on oil fuel as required by SDAPCD Rule 68, and with the airflow of these MS5000 machines at about 950,000 lbm/hr, this corresponded to 140 lbm/hr of NO2 when expressed at 15% O2 as required by LAAPCD Rule 67. Hilt and Waslo, (Ref. 1) and Hilt, et al (Ref. 2, 3) provide summary discussions of this work.