Experimental Study On Heat Recycling Synergy Pollutant Removal Of Flue Gas Deep Condensation

The flue gas contains a large amount of waste heat and SO₂,SO₃,fine particles and other pollutants,although the large-scale application of wet flue gas desulfurization effective control of the SO₂ emission,but wet flue gas still contains a lot of latent heat and a small amount of fine particles,SO₂ and other pollutants.The existing wet electrostatic and other end control technology were difficult to take the waste heat recovery and synergistic removal of pollutants both into account.Based on the theoretical analysis,this paper introduces a pilot test system of moist plume's condensation heat exchange and gaseous pollutants reduction,and the experimental system of SO₃ condensation mechanism.Then,introduces the waste heat utilization of flue gas after wet desulfurization and the removal behavior of fine particles,SO₂ and SO₃ in the process of condensation heat transfer.And a new thought is provided for improving energy efficiency,fine particulate matter removal,and the wet desulfurization efficiency's increase in the paper.First,based on the theoretical analysis,this paper introduces a test system of moist plume's condensation heat exchange and gaseous pollutants reduction,then tells the heat exchange performance of condenser for the moist plume after the wet flue gas desulfurization and the removal behavior of fine particles and SO₂ under different operation parameters.The study found that the condenser's heat transfer to saturated wet smoke after desulphurization works well,the recovery of condensation water is more than 90 percent.When the wet flue gas deeply condensates?The temperature drops from 50? to 20??in the heat exchanger,the removal efficiency of fine particles can be around 40 percent.To improve the concentration of fine particles in flue gas,to improve the flux of cooling water and to dwindle the flux of the flue gas can all enhance the removal efficiency of fine particles.Under certainly flue gas flow rate,the removal efficiency of SO₂ increase at first then decrease with the increasing of cooling water.The remove amount of SO₂ through condensation of wet flue gas will increase with the increase of SO₂ density in the entrance.When density in the entrance is about 200mg/Nm3,the total removal amount markedly increases,and hereafter the increase tends to be stable.And removal efficiency of SO₂ increases at first and then decreases.In the best experimental conditions,the removal efficiency of SO₂ can reach to 15?20 percent,and at this moment,adding calcium-based sorbent can raise sulphur removal efficiency observably.Secondly,this paper introduces the experimental system of SO₃ condensation mechanism,and the producing pattern of sulfuric acid mist and aerosol from SO₃'s condensation under different operating conditions.The study found that,when condensating under 100 degrees,collection efficiency of SO₃ increases with increasing of condensing temperature.When temperature comes to 100 to 120 degrees,almost all the SO₃ can be collected.When it increases continuously to passing the acid dew point of flue gas,the collection efficiency of SO₃ decreases rapidly.The increase of concentration of SO₃ and vapour both can lead to the decrease of SO₃'s collection efficiency through condensation,and the concentration of SO₃ impacts collection efficiency sharply.Under the same conditions,collection efficiency of SO₃:straight form condenser pipe<snakelike condenser pipe<snakelike condenser pipe with cotton filter.However,only adding the length of condenser pipe,works invalidly to the collection efficiency's increase.