Numerical Study On The Deposition Process Of Catalyst Particles In Flue Gas Turbine

Flue gas turbine is a very important equipment in energy recovery system,which can effectively improve the energy utilization rate in normal operation,and the energy saving effect is very considerable.However,the scaling of the blade and the shroud has always been the main cause of its shutdown.The deposition of the catalyst on the wall is a necessary condition for scale formation.Studying the motion law of gas-solid two-phase in a smoke machine with tip clearance can provide a basis for long-term operation of the smoke machine.In this paper,based on the actual refinery flue gas turbine working environment,the deposition process of the catalyst in the flue gas turbine with tip clearance is studied through numerical simulation and programming.Firstly,the deposition model and the collision model are written as the program.By loading relevant programs,the motion characteristics of gas solid two phases in static blade,moving blade and blade tip were studied under smooth conditions and different roughness conditions respectively.The research shows that in the static blade,the decrease of the flow pressure energy,thermal energy,and the increase of the velocity are smaller than that of the mainstream.In the moving blade,the speed of mainstream is continuously reduced because of work,the gap flow does not work,and the speed increases first and then decreases in the influence of mainstream.Because of the pressure difference,a gap flow from the pressure side to the suction side occurs at the gap,and exists different degrees of vortices in the moving and static tip clearance.As the roughness increases,the decrease of the pressure and temperature of the flue gas and the increase in speed are reduced.,the working efficiency of the flue gas turbine decreases.However,at the tip clearance,the flow parameters of the flue gas are no longer affected when the roughness increases to a certain degree.The deposition of the catalyst on the static blade mainly concentrates at the root of the blade,and the deposition of the catalyst on the moving blade concentrates on the top and tip of the blade.The deposition of the catalyst on the rough wall surface is more obvious than on the smooth wall surface.As the roughness increases,the amount of deposition at the root increases.The catalyst deposition on the section of the casing corresponding to the pressure surface is larger than the section of the casing corresponding to the suction surface.The deposition area of the catalyst at the top of the moving blade is mainly concentrated in the first half.With the increase of roughness,the deposition amount of the catalyst on the casing and the top of the moving blade will increase.The particle size increases and the deposition rate decreases.With the increase of roughness,the deposition rate of particles with particle size ?1?m tends to decrease,The sedimentation rate of particles with other particle sizes increases,but particles with particle sizes >15?m are very little affected by the roughness.