Achieving Over 50 NO_x Reduction on a Utility Boiler Originally Equipped with Circular Burners and NO_x Ports Using CCV~® DAZ Burners and Advanced OFA

摘要

In 2007 Riley Power Inc. a Babcock Power Inc. company, retrofitted a 365 MW balanced draft, opposed fired boiler, with new low NO_x CCV~® Dual Air Zone (DAZ) burners and an advanced OFA system. This unit, located in the western United States, has thirty- two (32) burners, sixteen (16) on the front and sixteen (16) on the rear wall and is designed to burn pulverized Powder River Basin (PRB) coal to generate 2,498,500 lb/hr of steam at 1005℉. The unit has four (4) MPS 89 roll-wheel style pulverizers. The OEM circular burners and NO_x port system produced NO_x emission levels of approximately 0.35 lb/MBtu at full boiler load.The retrofit performance goal was to obtain NO_x emissions less than 0.15 lb/MBtu throughout the boiler load range. The combustion system modifications achieved NO_x emissions as low as 0.135 lb/MBtu but generally around 0.15 lb/MBtu at full boiler load and reduced load operation. Testing demonstrated that the installation of advanced CCV~® DAZ low NO_x burners resulted in over 50% NO_x reduction from a system already equipped with NO_x ports. This is a substantial NO_x reduction for an opposed fired unit that originally featured circular burners with OFA.