Studying the impact of flame temperature adjustment at the nozzles on the efficiency and operating quality of the pulverized coal fired boiler with w-shaped flame

Abstract

Pulverized coal fired boiler with W-shaped flame is a common type of boiler used in Vietnam for Anthracite coal that have low volatiles content, difficult to ignite and longtime of complete combustion period. With many nozzles arranged on both sides of the furnace wall in the downward direction to form a W-shaped flame in the combustion chamber, this structure allows prolonging the retention time of coal powder particles inside the combustion zone of the combustion chamber for competed combustion purpose. However, the uneven operation of the nozzles can form an uneven temperature zone inside the combustion chamber that causing slag formation and uneven heat exchange in the boiler's riser tubes. The article studies the effects of adjusting the flame temperature balance at the nozzles on the combustion process and the efficiency of the boiler for the appropriate boiler tunning. The tunning results show the ability to improve boiler efficiency and reduce slag dropping that affects the normal operation of the furnace.