Application And Research On Technology Route Of Ultra-low Emission Improvement In Small Thermal Power Plant

As the national air pollutant discharge standards get harder year after year,the case of air pollutants to achieve ultra-low emissions is the technical problems that coal-fired thermoelectric enterprises generally faced.Based on the existing equipment and characteristics of four 75t/h pulverized coal boilers in Qingdao Thermal Power Company,this paper studies the technical route of denitrification,dust removal and desulphurization process,determines the best transformation plan,achieves ultra-low emission targets and makes environmental protection of small thermal power enterprises have important guiding significance.Through research,we get the following conclusions:(1)For the burning of lean coal,hot air powder small pulverized coal boiler,the effects on the concentration of nitrogen oxides include the types of coal,pulverizing system start-stop and burner.According to the results of the analysis,the technological transformation routes consist of lean coal into bituminous coal and hot air to send powder into the lack of gas to powder.NOx concentration decreased from 550 mg/Nm3 to 350 mg/Nm3.The transformation can not only reduce the source of the NOx generation,but also help to reduce the follow-up flue gas NOx pollutant management costs and difficulty.(2)The best choice for NOx treatment in flue gas is SCR technology,and the denitrification efficiency is above 85%,reaching the ultra low emission standard with NOx concentration less than 50 mg/Nm3.(3)For this high concentration of thermal power plant dust and the old electrostatic precipitator,in order to achieve ultra-low emission targets,changing into the electronic bag compound dust collector is the best means,making the dust collector outlet concentration of 20 mg/Nm3 below.If it combines with the wet electrostatic precipitator,dust emissions can achieve less than 10 mg / Nm3.(4)For the original double alkali desulfurization system,in the case of retaining the advantages of double alkali and saving funds,optimize the system to achieve SO2 emission concentration of less than 35 mg / Nm3.Advanced and effective equipment system is an important prerequisite for ultra-low emissions,scientific and meticulous operation adjustment is an important guarantee to achieve ultra-low emissions,low-nitrogen combustion for the furnace,SCR denitrification system,double alkali desulfurization regeneration and tower spray and so fine,rigorous operation adjustment is essential.In these areas still need to run through the practice of the law,to study how to use automatic adjustment,intelligent control to achieve ultra-low emission targets.