Numerical Simulation And Experimental Analysis Of Multi-phase Flow In Spiral Ribbed Tube

In the process of coal liquefaction,the gas-liquid solid three-phase fluid in the tube of the heating furnace usually has a stratified flow due to the density difference under the influence of gravity,the gas phase space in the tube is too hot to coking.Coking not only causes great energy waste and economic loss,but also affects the safe operation of equipment,which brings great security risks.In this paper,the main research object is the long helical tube with spiral internal rib and make smooth spiral pipe as reference.Hoping through the research of tube multiphase flow,we can explore how the tube structure can influent the parameters of multiphase flow in pipe mixed degree,eliminate gas phase space of the near wall region,and analysis of its structural parameters is optimized at the same time.First,we did series experiments and numerical simulation on horizontal straight pipe in order to research gas liquid two phase flow model.Record gas liquid two phase flow model,,we can found that the experiments and simulation have high degree.Then,the spiral tube was used for numerical simulation and analysis,and the mixed degree of multiphase flow in the spiral tube with inner rib was better than that of smooth spiral tube.Study adopts the method of multiple parameters of the orthogonal experiment,building different physical model with different structure parameters,then use VOF model in FLUENT to simulate.Inspect pipe fluid flow in the process of mass eccentricity,changes in near wall area average gas holdup,pressure drop;By means of comprehensive equilibrium analysis and variance analysis,this paper analyzes the flow process of the spiral ribbed tube,and provides theoretical guidance for the optimization design of the structure parameters of the spiral internal ribbed tube.The results show that:(1)For the mass eccentricity,the influence of the head count is the most important,and the influence of the rib height and the helix Angle on the mass eccentricity is not significant.(2)The structural parameters of the internal ribbed tube have a certain influence on the pressure drop in the fluid flow process.The main order of the influence is spiral Angle,costal height and head count.(3)The structural parameters of the internal ribbed tube affect the average gas holdup in the near wall area of the fluid flow.The main order is the head number,the spiral Angle and the rib height.(4)hrough the analysis of the overall balance of the orthogonal experiment results,it is concluded that the optimization scheme for the spiral pipe Numbers 3,rib height is 2 mm,spiral Angle of 60 °...