Improvement And Application Of The Control Scheme Of Flue Gas Pollutant Ultra Low Emissions From 2×300MW Coal Fired Units

With the rapid development of economy in China in recent years, the relatively backward mode of development has brought serious environmental pollution problems, the persistent haze has threatened the people’s health. To this end, the Hebei provincial government requires all coal-fired power generating units must be completed before the end of 2015 to complete the transformation of flue gas pollutant emissions. Xingtai Guotai Power Generation Co., Ltd. since 2012, began planning environmental protection and emission reduction work, in view of the boiler for the transformation of low nitrogen combustion. After 2013, respectively, the desulfurization system transformation, the new flue gas denitrification system, denitrification extraction efficiency and new projects, such as wet electrostatic dust removal, and at the end of 2015 all reached the ultra low emission requirements.Selective catalytic reduction technology and limestone gypsum wet desulfurization technology is the mainstream technology, but these two technologies to meet the requirements of ultra low emissions, there are still some problems to be solved. In this paper, combined with 2 * 300 MW units in Xingtai Guotai Power Generation Co., Ltd. denitration and desulfurization of flue gas pollutants ultra low emissions reconstruction engineering practice, aiming at the scene field test, found in the running process of the specific issues and of denitrification and desulfurization control system control scheme of improvement and optimization, field test and running results show that removal nitrate ammonia spraying self adjustable input rate can reach 99.8%, desulfurization absorption tower slurry p H value can be stable within + /- 0.2%, other all interlock logic to maximize the reduced operation amount, improve the stability of equipment operation. Eventually the two units of flue gas pollutants ultra low emission value of NOx control below the 45mg/Nm3 and SO2 control below the 32mg/Nm3, emission value can satisfy the requirements for national NOx 50 mg / Nm3 and SO2 35mg/Nm3, also considers the requirements of environmental protection and economy.In this paper, the problems of the optimized control system are put forward, and the improvement measures are put forward, which can provide useful experience for the treatment and settlement of the same kind of coal-fired generating units.