Research On Atomization Performance And Stability Of SNCR Internal Mixing Atomizing Nozzle In Power Plant

At present,coal is still the main energy in our country and an important source of power generation.When coal-fired power plants generate power,a large number of nitrogen oxides will pollute the atmosphere and endanger human health.Therefore,denitration treatment of power plants is very important.SNCR technology is widely used in the denitrification treatment of coal-fired power plant as a mature technology for controlling NOx in the world.The atomizing nozzle is responsible for crushing the reducing agent into droplets and feeding them into the reaction furnace.The droplet size,diffusion range of the spray,momentum and depth of the spray have a crucial influence on the mixing and residence time of the reducing agent with the flue gas.It is the key technology for SNCR to control the ammonia injection..In SNCR denitration technology of power plant,the internal mixing atomizer is widely used because of its advantages.Therefore,it is of great significance to study the atomization characteristics of SNCR internal mixing atomizer for the application of SNCR denitration technology.This paper studies the atomization performance and stability of SNCR internal mixing atomizer in power plant.Firstly,the atomization performance of the porous internal mixing atomizer is analyzed,which is affected by the change of test parameters.It is found that the atomization angle,gas-liquid flow rate and droplet diameter are affected by the different operation conditions and gas-liquid injection modes.It is also found that the conditions of atomization angle and droplet diameter are different in different positions of spray.It is also found that the structure of the nozzle also affects the gas-liquid flow rate,atomization angle and droplet diameter.Secondly,based on the measured droplet size data,the spray stability of the internal mixing atomization nozzle is studied by means of statistical methods and related mathematical models.The result as follows.If the gas pressure is greater than the liquid pressure,the spray stability will be improved.The spray stability is different in different spatial locations,and there are unstable regions.Reducing the liquid entrance diameter of the mixing chamber can increase the spray stability.When the outlet diameter of the mixing chamber is too large,the spray stability will become worse.So when designing the nozzle,the outlet diameter of the mixing chamber should be reasonably designed to avoid oversize.