Abstract: Abstract:The ammonia spraying automatic control loop of the flue gas deNOx system of 2×600MW unit in Guangdong Yudean Zhuhai Jinwan Power Plant was introduced. There were problems in operation of SCR deNOx system of thermal power plant, such as the selection of the minimum ammonia injection temperature, the too frequent start/stop operation of the ammonia spraying system and the poor effect of the ammonia automatic spraying. The problems were described, and the reasons of the problems were analyzed. The solutions were proposed.

Key words: Keywords:full automatic control of ammonia spraying, minimum operation temperature, flue gas deNOx, selective catalytic reduction (SCR) technology