Analysis On Corrosion Cause And Process Study On Desulfurization,Denitration And Dust Removal Of CFB Boiler

In this thesis,the leaking reason of CFB boiler tube of one company and general running status was analyzed,macroscopic examination,chemical composition analysis,metallographic analysis,fracture morphology observation and EDS energy spectrum analysis etc.were carried out on the failure tube bundles.Combining with the field process parameters and experimental analysis,the results show that the failure of the tube bundles is mainly caused by the hot corrosion of the fusion ash in which the raw materials of Na,K,V,S etc.play an important role,so it is urgently reguired to carry out desulfurization,denitration and dust removal process.This thesis takes the existing flue gas pollutants discharge system of the two circulating fluidized bed boiler of Qingdao Oil Refinery&Chemical company as a research subject.By studying the circulating fluidized bed boiler pollutants generation mechanism,the existing furnace desulfurization,dust removal system process,as well as the newly added desulfurization,denitration and dust removal system process in order to meet the new standard of environmental protection,utilizing the existing pollutants control device for desulfurization,denitration and dust removal,analyzing various main factors affecting desulfurization,denitration and dust removal,taking into comprehensive analysis and making test plan.The result shows that through the EDV wet desulfurization process of Belco Company,WGS?Wet Gas Scrubber?process of Exxon Company and the comparative analysis of Labsorb process of Belco Company,the appropriate desulfurization process of CFB boiler of Qingdao Oil Refinery Company has been determined,that is EDV wet desulfurization process of Belco Company.By adopting this process,SO₂ emission concentration decreased from about 80mg/Nm³ to 50mg/Nm³,which is in line with the requirements of the new national environmental protection standards.Through the comparative analysis of SNCR process,SCR process and SNCR+SCR combination process,the appropriate denitration process of CFB boiler of Qingdao Oil Refinery Company has been determined,that is SNCR process.By adopting this process,NOx emission concentration decreased from about 150mg/Nm³ to 80mg/Nm³,which is in line with the requirements of the new national environmental protection standards.Through the comparative analysis between the electric bag dust removal process and bag type dust removal process,the appropriate dust removal process of CFB boiler of Qingdao Oil Refinery Company has been determined,that is bag type dust removal process.By adopting this process,the dust emission concentration is decreased from about 30mg/Nm³ to 20mg/Nm³,which is in line with the requirements of the new national environmental protection standards.The optimization of the process plan of desulfurization,denitration and dust removal was carried out,the emissions of flue gas pollutants of CFB boiler of Qingdao Oil Refinery Company are in line with the requirements of the new national environmental protection standards.