| China is the world's largest coal-consuming country,accounting for 50.3%of the world's total coal consumption.China has a large number of coal-fired power plants.At present,the annual coal consumption of coal-fired power generation in China is nearly 2 billion tons.The coal used for power generation is the most important of coal consumption.Because of the different composition of coal combustion,the total amount of soot emissions in China has remained high all year round.The state and local governments have issued various standards,regulations,and notification requirements for ultra-low emission modification.The dust emission concentration is not more than 5 mg/m~3,and the sulfur dioxide emission concentration is not greater than 35 mg/m~3.The current desulphurization and dedusting process of the coal-fired power plant can not meet the requirements of ultra-low emission,so it is urgent to upgrade the existing equipment.This paper discusses in detail the current status of flue gas desulfurization and dedusting technology for 2×300 MW coal-fired power plants,the paper chooses the control technology of ultra low emission desulfurization and dedusting which can be matched with the company through analysis and comparison.The desulfurization process adopts the limestone-gypsum wet desulfurization process,the desulfurization reactor adopts the single-tower single-cycle desulfurization technology,and the number of spray layers is 5 layers.There is no bypass flue road,1 furnace and 1 tower are used for construction,and GGH is not installed,and the chimney is preserved treatment,the supercharged fan is not installed,the existing fan is to carry on the transformation.The ultra-low emission of smoke and dust is added to the upper layer of the absorption tower.The application effect and performance of ultralow emission desulfurization and dedusting technology are analyzed.The results show that improving the pH of slurry is beneficial to the desulfurization performance of the system.Increased flue gas flow rate will increase the desulfurization efficiency of the system,but will increase dust emissions;The efficiency of desulfurization and dedusting in liquid gas ratio system will be improved.The optimal operating parameters of the system are:the pH value of the desulfurization slurry is 4.5-5.0,the flue gas flow rate is 4m/s,and the liquid gas ratio is 18L/m~3.After the ultra low emission transformation of desulfurization and dedusting is completed,the ultra-low emission equipment can be continuously and steadily operated,The sulfur dioxide concentration of original flue gas of unit 1 is 2339.03mg/m~3,the sulfur dioxide concentration of net flue gas is 7.47 mg/m~3,the concentration of original flue gas is 38.04 mg/m~3,the concentration of net flue gas is0.97 mg/m~3,and the desulfurization efficiency reaches 99.6%.The sulfur dioxide concentration of original flue gas of unit 1 is 934.72 mg/m~3,the net smoke is 3.45mg/m~3,the concentration of raw smoke and net smoke is 29.18 mg/m~3 and 1.07mg/m~3,and the desulfurization efficiency is 99.6%.Ultra-low emission equipment can run continuously and stably,and can meet the requirements of the latest national flue gas emission standards.The paper has 28 figures,18 tables,and 85 references... |
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