Direct Numerical Simulation About Erosion Study Of Circular Tube By Coal Ash Particles With Considering The Coupling Heat Transfer

In recent years, the gas-solid two phase flow has a very important application in the field of engineering technology. One of the Applications is the coal-fired power plant boiler,The fly ash particles in flue gas will have serious wear and tear on the smoke flow of the metal surface,Which is the reason why the surface of heat exchanger appears phenomenon of corrosion,clogging and scaling,and these phenomena will lead to a significant reduction in the operating life of boiler. In order to prevent damages to the heat exchanger wall r,and thus bring threat to normal operation,the prediction research of wear is very important. Based on the research status at home and abroad,Numerical model study of circular tube on the surface of heat exchanger is feasible,and the direct numerical simulation of heat exchanger wall tube of collision and wear is less. This study adopts the method of direct numerical simulation,the research result has guiding significance for engineering design.In this paper,we used the direct numerical simulation method,the inter-coupling between the flow and the circular tube was to adopt the immersed boundary technology in combination with multiple direct force method,calculating the particle track by using Lagrange orbit model and considering the inter-coupling between particles and fluid. Programmed with Fortran,import the initial conditions,the physical parameters,model algorithm,simulated solution using the MPI parallel library. And differed from the related research before,this paper adopted a new wear model which is applicable to any material,any impact Angle and any impact speed,the model was put forward by researchers Oka et al,and others who come from the Japanese city of Hiroshima university based on the experiment. In addition,the article also further consideration to the impact of the temperature with the particles point model,the wear is studied,in different scale coal particles flow through the pipe surface of circular tube. Under the same flow condition,by change the pitch ratio or relative Angle of two circular tube,and then study the calculation results and analysis of the wear computation model,which is very meaningful to engineering guidance.