Optimization Of Hydrocyclone Based On Entropy Generation Theory

Hydrocyclone is being widely used by oilfield enterprises for its simple mechanism,easy operation and no revolving component.The research of hydrocyclone is focus on size and non size factors impact on separation efficiency of hydrocyclone.The evaluation of energy dissipation is mainly calculate by pressure drop,yet the research on the distribution of energy dissipation is rare.Analysis of the entropy generation is calculate value of entropy generation,to find distribution of energy dissipation by generation of irreversible phenomenon,and change operation parameters or design parameters to minimize the entropy generation,thereby achieve the aim which minimize the irreversible dissipation.Using the Mixture model and RSM model in CFD simulation software,Fluent,simulated flow field in Martin Thew two-cone hydrocyclone which have been widely studied.Derived some pressure and density contours of axial section,and derived some three-dimensional velocity distribution chart of cross section in column,large and small cone and end section.The result was matched with experiment.Derived some contours of entropy generation per unit volume.Found entropy generation is concentrate in overflow outlet and buffer area of large and small cone.Simulated impact of entropy generation and separation efficiency by eighty different models,which include five column length,ten large cone length and ten small cone length in 10%,15%,20%oil concentration and five overflow outlet diameter in 10%oil concentration.The results are as follows,the influence of entropy generation and separation efficiency owing to alternation of column length is small;Increasing large and small cone length,the turbulent entropy generation,viscous entropy generation and total entropy generation increased firstly and then decreased;When overflow outlet diameter less than five millimeter,the influence of entropy generation and separation efficiency owing to alternation of overflow outlet diameter is also small.When overflow outlet diameter greater than five millimeter,entropy generation and separation efficiency declined sharply.Increasing oil concentration,separation efficiency declined and alternation of entropy generation is unapparent.To aim at minimize the entropy generation as far as possible meanwhile keep separation efficiency,determined a optimization scheme and carried out numerical simulation.Comparing the original model,total entropy generation reduce 48.91%,separation efficiency decrease slightly.Based on the optimization scheme,changed the two-cone hydrocyclone to single cone hydrocyclone and carried out numerical simulation.Comparing the original model,total entropy generation reduce 57.35%,and keep a higher separation efficiency.Therefore we can consider that this model is a high efficiency and energy saving oil-water separator hydrocyclone.The above results make a reference for the optimization design and also it is important for further research.