Study On SCR Denitration System Design And Its Flow Characteristics In 330MW Units

NO_x,SO_x and dust,emitted from power plants,contribute to the majority precursors of PM 2.5.The wide application of ultra-low emission technology will improve the cleanliness level of Chinese energy structure which mainly relies on the consumption of coal.And the application can also provide a new method assisting the development and surviving of the coal power.As for the deNO_x process in large coal-fired power plants,the most used are the low NO_x combustion technology and the NH3-SCR process.Furthermore,to ensure the emission of NO_x lower than 50mg/Nm3,it is very crucial that the NH3-SCR is operated efficiently and stably.The key to the successful implementation of SCR is to ensure the uniformity of flow field and flue gas temperature in the reactor,and the complete mixing of reducing agent and flue gas.According to the above,this paper firstly aimed to promote the deNO_x system of super clean emissions in a 330 MW unit of one coal-fired power plant.Then,the mathematical model was established,and the flow mixing characteristics of SCR denitrification system are studied by numerical simulation.The calculation results show that the flow guide plates in the flue and reactor of the SCR system is reasonable.The velocity distribution at the entrance of the first layer of catalyst in the SCR reactor under BMCR conditions is uniformthe(The standard deviation is 11.99%).The flue gas incident angle is little(7.45 o);Ammonia is fully mixed with flue gas(The standard deviation of ammonia concentration distribution was 2.21%).Temperatures change in ±2.7?.The pressure loss of the denitrification system is 729 Pa.The above results indicate that the design of SCR reactor,guide plates,ammonia injection grid,static mixer and other parts is reasonable,Laying a solid foundation for the deep removal of NO_x.Finally,the cold state physical model experiment was established by the modular calculation,and the flow mixing characteristics in the SCR flue and the reactor were studied.The results show that the velocity distribution at the entrance of the first layer of catalyst,the incident angle of the flue gas,the concentration distribution of the reducing agent and the pressure loss of the system under BMCR condition and 30%BMCR were in good agreement with the calculated results,which further shows that the design of SCR denitrification system is reasonable.At the same time,it also shows that the mathematical model of SCR denitrification system is reasonable and credible.The results of this paper can provide reference for the design of similar products in the future.