Application And Research Of SNCR Denitration Technology For 300MW Circulating Fluidized Bed Boiler

In recent years,NO_X emissions have shown a rapid growth momentum.The circulating fluidized bed(CFB)boiler has become an environmentally friendly boiler because of its wide fuel adaptability and low combustion temperature,resulting in low NO_X emission concentration.With the increasingly strict national environmental prote-ction policy,the NO_X emission level of CFB boilers has not been able to meet the current requirements,so it must be denitrified.In practical engineering applications,CFB boilers have become mature with selective non-catalytic reduction(SNCR)deni-tration technology,but there are still some problems and deficiencies,so it is necessa-ry to carry out engineering application research.Based on the 2×300MW CFB boiler and its denitrification project of Xukuang Power Plant,this paper establishes a model through thermodynamic theory and uses urea solution as reducing agent to calculate the change value of boiler efficiency after adding SNCR denitration system to Xukuang Power Plant.The efficiency loss is just0.21%,which is in line with industry standards.At the same time,the influence of denitration system on boiler efficiency under different ammonia-nitrogen molar ratio(NSR)and reducing agent concentration is analyzed,and the feasibility of using urea-SNCR denitration technology scheme is demonstrated.The CFD simulation software was used to simulate the thermal state of the denitration system SNCR process,and the NO_X emission of the#1 unit of Xukuang Power Plant was monitored in real time.The average value was less than 50 mg/Nm~3,and the denitration effect was significant.According to the operation of#1 unit under variable working conditions Parameters,comprehensive comparison to obtain a denitr-ation system using a molar ratio of ammonia to nitrogen of 1.0 to 2.0,a concentration of 7.5%to 10%of the urea solution can achieve higher denitration efficiency.In addition,the construction cost of the SNCR system is 32 million yuan,and the total operating cost is 15.2825 million yuan/year,which is economical compared with the SCR system;combined with the denitrification project,the relevant technical trans-formation work is actually completed,and the system is stable after the transformati-on.