Unsteady Numerical Simulations Of 3D Turbulent Flow In Molten Salt Pump

Research works in this paper were financed by the item of education department of Jiangsu province "study and industrialization of molten salt pump"(JHB05-38).Molten salt pump is a kind of vertical centrifugal pump,and used on the transportation of high temperature nitrate,nitrite and ionic membrane caustic soda.It is also widely used in the chemical process of trimerization hydrogen amine,salt manufacture,alkali manufacture, carbamide manufacture and et al.Its operation temperature is between 250℃to 400℃.The underwater part of volute molten salt pump was unsymmetrical,and the thermal deformation was also unsymmetrical.The sliding bearing was easily to be spoiled due to high temperature.In recent years,many companies used vaned bowl diffuser as discharge chamber,and its underwater part was symmetrical.The side discharge was avoided.To explore the basic flow law of molt salt pump with vaned bowl diffuser,based on the former research works,a molten salt pump was designed and its three-dimensional incompressible unsteady turbulence flow field was calculated. The main works are showed as following:1.Present research states of molten salt pump interior flow were summarized.The hydraulic design method was expatiated.Based on this theory,a molten salt pump was designed.2.Pro/ENGINEER Wildfire 2.0 was applied to sculpt the molten salt pump.3.The CFD pre-processing software GAMBIT was used to divide grids of the pump passage.4.Standard k-εturbulent model and moving mesh method in FLUENT were adopted to simulate internal three-dimensional incompressible unsteady turbulence flow field at the various flow rates.The basic flow field distribution in vaned bowl diffuser passage was obtained.5.The overall performance of molten pump was predicted by calculation.These data of CFD are compared with experiment.By the former works,the main conclusions are shown as following:1.Rotor-stator interactions between impeller and diffuser are very evident,and they show a periodic rule. 2.At the low flow rate condition,the vortex appear in the diffuser and make the passage crowded.3.CFD method is convenient,and could describe the flow field of molten salt pump well.