Research On The Modification Of Ultra-low Emission For Longshan Power Plant

With the increasing emphasis on environmental protection in our country,the emission standard of thermal power plants is more and more strict.Longshan power plant is located in Hebei region,and requires pollutant discharge to achieve Ultra-low emission standard.The emission of nitrogen oxides,soot and sulfur dioxide should be lower than50mg/Nm³,5mg/Nm³ and 35mg/Nm³.The current status of NO_X emission was analyzed,and two aspects of low nitrogen combustion and flue gas denitrification were proposed to reduce the concentration of nitrogen oxides.Aiming at the problems existing in the burner before modification,the burner was retrofit.After modification,the concentration of NO_X in the furnace outlet decreased from 1000mg/Nm³ to less than 600mg/Nm³.The three schemes of SCR,SNCR and SCR/SNCR were compared.SCR was selected as the denitrification transformation plan of flue gas,and the transformation plan was introduced in detail.At the same time,the parameters of ammonia consumption,SCR size and catalyst quantity were calculated in detail.The layout of the flue guide plate is optimized by the way of CFD simulation.After the transformation of flue gas denitrification,the concentration of nitrogen oxide decreased to less than 50mg/Nm³.Different dedusting and transformation technologies were compared.The WESP was selected as the retrofit plan of the dust removal,and the WESP with the conductive FRP anode type was selected.After the modification,the dust emission concentration decreased from 30mg/Nm³ to less than 5mg/Nm³.The different revamping schemes of desulfurization tower were compared,and single tower double circulation was selected as the revamping scheme for desulfurization.At the same time,the original GGH was dismantled,and the supporting system such as absorbent preparation and supply system,gypsum dewatering system and so on were compatibilized.After the modification,the SO₂ emission concentration was reduced from200mg/Nm³ to less than 35mg/Nm³.The emission of nitrogen oxides,dust and sulfur dioxide has all reached the standard of ultra clean emission after the ultra clean emission environmental modification.