| When the fluid containing solid particles as the working media through the impeller,solid particles will inevitably impact,friction,and wear,rebound with the blade and accumulation will also be formed on the impeller,these actions are harmful to flow field of fan and can degrade the performance of the fan and transmission capacity,even cause major accidents.Therefore,it is of great significant to study deeply the effect of solid particles on the wear of blades and the performance of fan.The change of the installation angle of the moving blade affects the wear pattern of the blade,so that the performance of the axial flow fan is different.The particle size,particle mass concentration and running time have certain influence on wear pattern of the blade.A 3D numerical simulation on a single-stage axial fan of type OB-84 is carried out using Fluent to investigate the blade erosion regimes and fan performance.The particle trajectories,the particle mass concentration on the surface and blade wear regularity under different blade installation angles of 29°,32° and 35° are investigated,and the effect of blade wear on fan performance is compared.The important features including particle trajectories under different particle diameters,erosion pattern and particle mass concentration distribution on the pressure and suction surfaces are examined,and the effect of particle mass concentration on erosion rate is analyzed.The results show that the blade wear mainly concentrated in the pressure surface in front edge position,the blade tip and two-thirds to three-quarters of leaf height.With the increase of moving blade installation angle,particle concentration in the trailing edge increased and trailing edge wear become worse.The fan conveys dust airflow and runs after a period of time,fan total pressure drop slightly,the efficiency is significantly reduced,and with the increase of flow rate,the efficiency decline gradually decreased;Within the range of flow rate,the average efficiency decline of three kinds of moving blade installation angle is 4.3%,4.0% and 2.8%.With the increase of particle size,the particle trajectory line gradually deviates from the air flow,the impact point of the particles on the surface moves forward.Compared with the blade wear rate,particle size has great influence on blade wear patterns: with the increase of particle size,the front edge of pressure surface increasingly serious wear,and the wear of trailing edge is slightly reduction,the wear focus on front edge gradually.The wear rate on the front edge and the trailing edge of the suction face is worse and the wear area is increased.The particle mass concentration has a great influence on the wear rate of the blade,and the effect on the blade wear is not obvious. |
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