Simulation Study On Mixing Performance Of Liquid-Liquid Ejector To Storage Tank

With the ever increasing demand for biological fuels the need to transport and store such products rises too.Rapeseed oil or biodiesel are collected and stored intermediately in large storage tanks,often with a volume of more than 10,000 m3.During its storage period in the tank this oil is kept in constant movement to prevent de-mixing or settling taking place.A widespread possibility of implementing this mixing operation is the application of liquidliquid mixing ejectors.The fundamental advantages of utilising it instead of mechanical mixing systems may be found in the low investment costs and the practically maintenance-free operation mode?There are few studies on this mixing system at home and abroad,most of which are focused on the study of mechanical mixing systems.In this paper,the performance of the liquid-liquid ejector is simulated and analyzed.The numerical simulation of the three-dimensional flow field in the oil storage tank is carried out by using the CFD software.Look the mixing performance of storage tank at different conditions with help of liquid-liquid ejector.The main research work of this paper is as follows:(1)The two-dimensional geometric model is established.The CFD ICEM software is used to establish the grid and the boundary conditions are set.The turbulence model is validated and selected.Using the Standard k-? turbulence model to simulate inner flow field of ejector.We can collect much detail information about inner flow field of velocity and pressure.(2)The effects of different structural size parameters and operating parameters on the performance of the liquid ejector are studied.The results show that the ejectior coefficient increases with the increase of the diameter of the mixing chamber and noozle outlet.With the increase of nozzle-to-throat clearance,the ejectior coefficient is increased first and then from the ejectior coefficient of about 3.4,the ejectior coefficient increases slowly.With the increase of the outlet pressure,the ejection coefficient of the ejector is decreasing.With the increase of the pressure of the suction fluid,the ejectior coefficient increases;Changing the mass flow rate of the working fluid of the ejector increased 134.5%,while the injection coefficient varied from 3.51 to 3.56 and increased only by 1.4%(3)Finally,in the case of installing one and two ejectors in the simplified model of the oil storage tank,simulating the whole flow field of the oil storage tank by using CFD software.and the change of the internal flow field in the oil storage tank is analyzed.The mixing effect of the liquid ejector on the fluid in the oil storage tank is evaluated the velocity distribution in the flow field.