Mesoscopic Impactor Filters Model And Analysis Of Radioactive Aerosol Collection

Once the failure of nuclear reactor happened consistent with small break loss of coolant accident,the huge radioactive aerosols will soon be emitted into the containment vessels,which may cause the pressure will raise.So as to diminish the pressure while not emission polluted of the atmosphere and humans being,the radioactive particle can't be directly releases.It is so necessary realize economical methodology to filtrate the particle contaminants before emission.Therefore,it is necessary to use appropriate filtration devices to avoid the diffusion of such radioactive aerosols into the atmosphere.The filters is very important device for particle collection,and it is used in different industry processing,especially for the radioactive aerosol collection for nuclear power plant.This study established the 3-D geometries with different structures of mesoscopic inertial impactor filters model,to explore the particle movement and deposition inside the filters.The model of the filter was established with the commercial software of ICEM CFD and the meshes were divided accurately.We supposed that the radioactive aerosol particles are uniformly seed at the inlet housing nozzle,and each one of the assumptions and boundary conditions are set to agree with the nuclear power plant conditions.The first flow calculations in this work were performed without particles and second flow simulation were performed with seed particles in the inlet nozzle.The radioactive aerosol collection efficiency and pressure drop profile of the inertial impactor filters were investigated by numerical simulation.Additionally,fluid properties and parameters of aerosol particle were examined,and subsequently it was obtained that the variations in key factors(for example gaseous stream velocity,aerosol particle diameter and inlet diameter)had important influences on collection efficiency.The model was used to study the influence factors on collection efficiency.It was found that if the pipe length was constant,the collection efficiency increased in response to decreasing the inlet diameter,also collection efficiency for same inlet diameter raised smoothly in response to decreasing the turning angle.In addition,in which diameter of round nozzle was constant,collection efficiency improved in response to increasing the pipe length.