Research And Application Of Emission Reduction Technology Of Soot And SO₂ In 300MW Coal-fired Power Plant

China's energy consumption with the rapid progress of national economy and the rapid development of industrial technology and the rapid increase of thermal power is the main form of energy production and supply capacity,the industry has been developing rapidly,but also brought environmental pollution,environmental emission standards in the past 10 years with the development of environmental technology constantly improve.The installed capacity of China Aluminum Limited by Share Ltd Lanzhou branch(3 x 300MW)power plant is 3 × 300 MW.The #1,#2 and #3 units have been put into production in 2008.The desulfurization system adopts limestone gypsum flue gas wet desulphurization,one furnace and one tower configuration,and the pulping system is purchased by external limestone aggregate,wet grinding and pulping,with 2 vacuum belt machines and other public utilities.Zhejiang feidahuanbao Polytron Technologies Inc precipitator using electrostatic precipitator,each furnace with 2 double room four electrostatic precipitator,a total of 16 ash bucket.The design efficiency of dust removal is 99.5%,and the content of dust at the entrance of electrostatic precipitator is designed to be 12900mg/Nm3.The dust content in the outlet of the dust collector is less than 100mg/Nm3(standard cubic).The actual emission concentration of SO2 in the power plant is at 250mg/Nm3 for many years,and it fluctuates over 300 mg/Nm3 in winter,and the discharge of discontinuous exceeding the standard is more frequent.The average dedusting efficiency of the dust collector under the BMCR condition is 99.25%,which is quite different from the design efficiency 99.5%,and the emission exceeds the standard at about 50 mg/Nm3.According to the emission standard of air pollutants in thermal power plants(GB 13223-2011),the SO2 and soot emission concentrations are implemented at 50 mg/Nm3 and 20 mg/Nm3 respectively.Therefore,the current desulfurization system and dust removal system must be upgraded.The transformation difficulties of wet FGD system: one is the difficult arrangement,the modification scheme is compared to determine the direction;two is the space layout of compact design,no new facilities,the expansion to meet the load calculation in the original infrastructure;three is the original absorption tower after the expansion must satisfy the efficiency requirements;four is reformed the supporting public system supporting the expansion;five is the export of absorption tower in the modified demisting efficiency of accounting;six is the unit outage time is very tight,large quantities,difficult construction organization.The main difficulty is the transformation of the original desulfurization dust emission front ESP transformation space is extremely limited,a wide range of transformation plan is limited in space,optimization of technical scheme after calculating and choosing the conductive filter non mainstream technology to solve the existing difficulties of electric dust emission reduction,according to PM10,PM2.5 and gypsum rain requires the presence of GGH removal after the selection of the type of wet electric dust collector scheme to solve the problem,no problem to determine the accounting basis reform scheme.At the same time,after the transformation of the desulfurization and dust removal system,the overall resistance of the system is restricted.In order to solve the environmental problems caused by the GGH equipment failure,the system resistance changes after the transformation of the furnace system need to be reformed and the resistance of the accounting system is selected for fan selection.In view of the requirements of wet flue gas emission,the existing methods of chimney anticorrosion are compared and calculated to solve the problems of corrosion,diffusion and gypsum rain caused by the discharge of wet flue gas.This research mainly aimed at the research to solve the existing difficulties in the design,the calculation and transformation test proved that the above difficulties have been solved,the operation of the unit in the transformation period under the condition of the environmental protection emission standard system,stable operation,and made the corresponding social and business benefits.