| The rotating-sleeve distributing-flow system for reciprocating plunger pump achieves efficient flow distribution by using the linear reciprocating motion of the plunger to drive the rotation of the rotary sleeve in one direction,and has been widely used.However,the lubrication characteristics between the rotating-sleeve and pump body distribution pair are one of the important factors that affect the overall performance and service life.In order to provide the theoretical basis for the optimal design of the flow distribution pair in the reciprocating piston pump rotary flow distribution system,this paper takes the water lubricating film between the rotating-sleeve and pump body of reciprocating plunger pump as the research object,and proposes a new algorithm that combines FLUENT software and FORTRAN programming.The results were analyzed by ORIGIN software.The work completed mainly includes:(1)The distribution pair of rotating-sleeve distributing-flow system for reciprocating plunger pump composed of pump body and rotating-sleeve was regarded as a special sliding bearing to analyze the lubricating film characteristics.The rotary-sleeve was regarded as the journal and the pump body was regarded as the bearing hole.(2)The flow field of the pump and the spring force between the plunger and the rotary-sleeve all change periodically with the rotation of the rotary-sleeve.Therefore,the lubrication analysis of the distribution pair belongs to the complicated variable speed and variable load periodic lubrication problem.In order to simplify the problem,the rotating-sleeve and pump body distribution pair is considered as a special radial sliding bearing,and the quasi-steady state solution is solved for a specific instant.A new algorithm is proposed and verified.Under the condition that the initial eccentricity and the angle are preset,the periodic variation of the overall macroscopic flow field characteristics of the reciprocating plunger pump is simulated by using the User-defined-function,the dynamic mesh and the slip mesh technique in the FLUENT software.Then,the combined force of the pressure of the fluid in the pump cavity,the force of the spring and the force of the outlet pressure on the lubricating film is taken as the additional load of the lubricating film.The Gauss-Seidel method is used to calculate of the lubricating film between the distribution pair which is regarded as the sliding bearing.According to the error between the eccentricity and the deflection angle and the preset values,the eccentricity and angle set before are relaxed,as well as the simulationof the flow field and numerical analysis is repeated to achieve the convergence accuracy.So the eccentricity and deflection angle of the rotary-sleeve at a certain instant can be obtained.The calculation results show that this algorithm is feasible.(3)The influence of the radius clearance,the aspect ratio and the structure of the distributing slot on the characteristics of the lubricating film was studied under three transient conditions.The results show that under a given working condition,the radius clearance is between 10 and 20 microns,the aspect ratio is between 1.25 and 1.4,and the arc distribution slot can ensure the lubrication performance.(4)The influence of the depth of the inflow and outflow cavities on the lubricating film between the rotating-sleeve and the pump body was studied.The results show that with the increase of the depth of the inflow cavity,the thickness of the lubricating film corresponding to the position of the inflow cavities becomes larger,while the minimum film thickness in the pressure bearing area decreases,and the minimum film thickness shifts in the circumferential direction;the maximum pressure in the pressure bearing area increases,and the maximum pressure position corresponds to the minimum film thickness position.When the depth of the inflow cavity is increased to more than 8 micron,full-film lubrication may not be formed between the rotating sleeve and the pump body,resulting in failure of lubrication.Therefore,the depth of the inflow cavity should not be greater than 8 micron. |
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