Abstract: At the present time quite a lot of new units put into operation unceasingly and many older units need to build environmental protection equipments in our country. According to the Retrofit experience of the desulphurization system of 600 MW unit in the third stage project and the operation problems of 1000MW unit in the forth stage as well as the accident occurred in the electric precipitator in recent years at Zouxian Power Plant, this paper discussed their advantages and disadvantages, and presented the overall plan scheme about flue gas desulphurization and denitrification in order to avoid investment with repetition.

Key words: environmental protection equipment, equipment retrofit, flue gas deSO2／deNOx, dust removing