Hydraulic Performance Analysis And Structural Improvement Of Suction Manifold For Fracturing Pumps

In this paper,the working principle of the disintegrated pump equipment and the status of the suction performance of the fracturing pump at home and abroad are introduced.In view of the poor inhalation performance of the pipe,such as disconnection,sediment,cavitation,noise and vibration during the inhalation process at present,the Fluent fluid soft parts are used to simulate the pressure of the flow field of the suction pipe and the pump valve.The structure of the suction manifold is improved by calculating the resistance loss of the pipe and the pump valve and the cavitation of the hydraulic cylinder,thereby improving the suction manifold suction performance and prolonging the service life of the fracturing pump.Firstly,the layout of crank initial angle of five cylinder reciprocating pump is optimized.According to the influence of the instantaneous flow fluctuation of each section of the five cylinder reciprocating pump on the suction performance of the pump,the combined optimization calculation method of the instantaneous flow rate of each cylinder is established by the dimensionless idea,and 8 better layout schemes are selected.In addition,from the strength of the crankshaft,the crankshaft stress and bending moment in the process of discharge are analyzed.By comparing the influence of the bending moment of the crank corresponding to the No.3 liquid cylinder,two optimal arrangement of the initial angle of the crank is determined.These 2 optimization schemes effectively reduce the additional inertia head loss caused by inhalation liquid and reduce the problem of pipeline breaking and settling.Then a simplified model of fracturing pump valve is established,and the flow field of fracturing pump valve is numerically simulated.Because the connection between pump valve and suction manifold,the performance of pump valve directly affects the inhalation performance.When simulating the pump valve,according to the motion characteristics of the valve disc,the rule of the lift,speed and acceleration of the valve disc during the movement of the valve disc are grasped.Furthermore,the dynamic grid is generated by UDF compilation,and the pressure of the pump valve,the pressure in the cylinder and the cavitation of the liquid cylinder under the different punching and different cone angles are analyzed when the crank angle is moved between 0°~180°.So the optimum pump valve punching and cone angle in the process of inhalation are selected.Based on the above two parts,numerical simulation is carried out for the variation of flow pressure during suction process of suction manifold.By understanding the main factors that affect the suction performance of the suction pipe,the Fluent software was used to analyze the outlet pressure of the suction pipe in 13 kinds of suction pipe,such as the pipe diameter,the angle of different inclination,the corner of different branch pipes and the gradually shrinking pipe diameter,and the resistance loss of suction manifold under different structures is obtained.In addition,the Fluent solid-liquid two phase flow is used to simulate the effect of 5 typical suction pipe remittance structures on the sediment sediment,and the volume fraction of solid particles under different pipe remittance structures is compared,and the better pipe remittance structure is selected.Finally,the influence of suction manifold on the cavitation of liquid cylinder is numerically simulated.Through the structure of 8 different suction pipe sinks connected with the pump valve,the flow velocity and cylinder movement process of the suction pipe in the suction process are controlled by Fluent dynamic mesh UDF,and the cavitation of the fluid cylinder under the conditions of different pipe diameter,different pipe inclination angle,different branch corner,different cone angle and the condensation structure of the general pipe are respectively analyzed.By comparing the cavitation value of the cylinder,the larger pipe diameter,the smaller inclination angle,the smaller corner of the branch pipe and the 60°of the cone angle of the pump valve,the cavitation value is smaller.