| Jet pump is a fluid machinery and mixing reaction equipment used to transfer mass and energy.It is widely used in the industry with many advantages such as no moving parts,structural integration,easy installation and maintenance.Among them,in the fields of jet aeration,sewage treatment,and biopharmaceuticals,the quality of the mixing effect has become an important performance evaluation parameter of the jet pump.However,the current research on the mixing effect of the jet pump mainly focuses on the optimization of structural parameters and changing the structure of the fluid outlet,and the research on the important mixing site-the throat is insufficient.This paper proposes a new type of jet pump,the built-in vane jet pump,which improves the mixing efficiency of the jet pump by building multiple rows of fixed vanes in the throat on the basis of the ordinary jet pump.This method has the advantages of simple processing.,not easy to damage and other advantages,and does not change the original features of the jet pump,such as no moving parts and integrated structure.And through the numerical simulation of the built-in vane jet pump,the conclusions are as follows:(1)The built-in fins as a whole can improve the mixing degree of the two-phase fluid inside the jet pump.Compared with the ordinary jet pump,the maximum non-uniformity coefficient at the outlet can be reduced from 0.2534 to 0.0743.And the mixing effect and efficiency are not incompatible,and there are some structures that improve the degree of mixing without reducing the efficiency.(2)In different arrangement of fins,the influence of fin row number and size parameters on mixing degree and efficiency is inversely proportional,that is,the increase of row number and size leads to a decrease in efficiency while improving the mixing effect;The effect is proportional to the effect of efficiency;the parameter of the distance between the first fin and the throat inlet has a more complicated effect on the flow field.Generally speaking,a small spacing should be selected under low flow ratio,and a larger spacing should be selected under high flow ratio.In addition,the change of the flow ratio will lead to the change of the influence trend of some factors on the mixing effect.(3)In different arrangements of fins,the influence of the number of fin rows and size parameters on the mixing degree and efficiency is inversely proportional,that is,the increase of the number of rows and the size of the fins increases the mixing effect and leads to a decrease in efficiency;The influence on the mixing effect and efficiency is positively correlated;the influence of the parameter of the distance between the bow vane and the throat inlet is very complex.Generally speaking,the spacing should be smaller at low flow ratios,and larger spacing should be selected at high flow ratios.In addition,the primary and secondary effects of the four parameters on the mixing effect are the number of fin rows > the distance between the first fin and the throat inlet > the fin spacing > the fin size,among which,the change of the flow ratio will lead to the change of the influence trend of some factors;The primary and secondary influences on the efficiency are the number of fin rows > the distance between the bow fin and the throat inlet > the fin spacing > fin size,and the change of flow ratio has little effect on the level of each factor.(4)The arrangement of the large fins at both ends and the small fins in the middle has the best mixing effect,and when the fin structure is small,the longitudinal rotation of the fins can improve the mixing degree of the two internal fluids,but On the contrary,under the condition of large fins,it will lead to the increase of the non-uniformity coefficient at the outlet.(5)By building a test bench,the external characteristics test of the ordinary jet pump and the built-in vane jet pump in the numerical simulation is carried out,and the correctness of the numerical simulation is verified by collecting the test results. |
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