The Characteristics And Analysis Of Desulphurization Ultra-Low Emission Modification Operation Of 600MW Unit

China is a country with coal as the main energy source.Coal production ranks first in the world,and high-sulfur coal reserves account for 20%-25%of total coal reserves.The main sources of sulfur dioxide pollution from coal combustion are three aspects:First,domestic pollution,including harmful gases emitted by fuel into the atmosphere during diet or heating;The second is industrial pollution,including thermal power generation,iron and steel and non-ferrous metal smelting;Third,traffic pollution,including vehicles,aircraft,trains,ships and other vehicles discharge gas.China's annual total emissions of sulphur dioxide far exceed the environmental self-purification capacity,and sulfur dioxide emissions from coal combustion account for more than 40%of the total emissions.Strict control of sulfur dioxide emissions from coal-fired power plants is of utmost importance.The Shanxi Provincial Economic and Social Affairs Commission issued relevant policies requiring coal-fired generating units to complete ultra-low emission transformation by the end of 2020,of which the emission limit of sulfur dioxide is 35 mg/Nm³.In order to meet the requirements of flue gas pollutant discharge,Yuncheng Power Company decided to carry out ultra-low emission transformation of desulfurization facilities of two units.This paper takes the SO₂ ultra-low emission reconstruction project of two600MW thermal power plants of Yuncheng Power Company as the research object,and combines the actual situation on the spot,determines the equipment parameters needed for the renovation system and sets of two renovation plans,considering the amount of reconstruction and the duration of the renovation.Decided to adopt the first option:adding a turbulent ballast.According to this,a turbulent ballast was added between the original first layer of the spray layer and the inlet flue.The original three slurry circulating pumps were still used,and two high-lift slurry circulating pumps were added to the original two-level roof defogging device.Add a layer of pipe defogging device.The operation characteristics of desulfurization before and after ultra-low emission transformation were compared and analyzed.After the renovation,each desulfurization system was well operated,and the sulfur dioxide emission concentration reached the limit standard,and it successfully passed the monitoring and acceptance of the Environmental Protection department.In more than a year of operation,they have achieved continuous and stable emission standards.In addition,under the condition that the desulfurization discharge is up to the standard,the selective suspension of the slurry circulation pump has reduced the power consumption of the desulfurization system,reduced the plant power consumption rate,and achieved the purpose of energy conservation.In addition,the theoretical analysis of the factors affecting desulfurization efficiency plays a guiding role in optimizing and adjusting desulfurization operation and improving desulfurization efficiency.The research results show that:1.The retrofit scheme is feasible.Under the premise of coal quality stability,the desulfurization system fully meets the requirements of various load conditions of the boiler.2.Under different load conditions,according to the desulphurization efficiency and the concentration of SO₂at the exit of the absorption tower,the pulping pump is stopped and the energy-saving effect is obvious.3.SO₂ ultra-low emission transformation achieved the expected goal and fully met the SO₂ emission limit of 35 mg/Nm³.required by the Shanxi Economic and Social Affairs Commission.