Investigation Of Particle Impact On 304SS Under The Liquid-Solid Two Phase Flow

With the rapid industrialization,the demand for energy is increasing day by day.Meanwhile,the environment pollution is more serious than ever before.Therefore,the adjustment of energy structure becomes more and more important and urgent.Nuclear energy which has the characteristics of environmental protection,clean and high energy density makes up for the low energy density of the new energy and avoids the harm of the traditional fossil energy to the environment.Since 1954,the world's first nuclear power plant connected to the grid,the development of nuclear power has been greatly improved,but its security has affected the sustained,stable and long-term development of nuclear power.During the operation of the nuclear power,the granular corrosion material such as iron,copper,fine sand will be produced.The flowing liquid which mixed with the corrosion products becomes into solid-liquid two-phase flow in the two circuit and the three circuit of the nuclear power plant piping system operation.The wear and corrosion behavior of liquid solid two phase flow will cause the loss of the material and the failure of the equipment.This article investigated stainless steel erosion using experimental and numerical method.Particle size,particle trajectories,particle-wall impact points and the change of the surface characteristics of materials were considered which is few in the existing research,thus,this research is innovative and referential.By simulating and experimenting,it is found that,in the sand-liquid two-phase flow,the main factor of material loss,material accumulation and surface flaking is the effect of the impact of sand and surface.It was found that the mean velocity near the core region of impinging jet had similar trend at various radial distances.A stagnation region was found under the impinging jet,where pressure was higher than that in around area.The particle trajectory determines the distribution of the impact point and the wear area of the sample surface.In addition,numerical simulations were conducted in terms of particle concentration and particle diameter,the results of meanerosion ratio agreed well with experimental data.The erosion distribution on the sample predicted was found as the same as that observed by microscope.Considering the particle behavior and the structure and properties of the material surface,further reveal the erosion-corrosion behavior of AISI 304 stainless steel in an impingement system from microscopic angle which have significant importance for the rupture of protective material and safe operation of nuclear power.