A computational fluid dynamics model to evaluate the inlet stroke performance of a positive displacement reciprocating plunger pump

摘要

A computational fluid dynamics model of the middle chamber of a triplex positive displacement reciprocating pump is presented to assess the feasibility of a transient numerical method to investigate the performance of the pump throughout the 180° of crank rotation of the inlet stroke. The paper also investigates, by means of computational fluid dynamics, the pressure drop occurring in the pump chamber during the first part of the inlet stroke in order to gain a better understanding of the mechanisms leading to cavitation. The model includes the compressibility of the working fluid and the lift of the inlet valve as a function of the pressure field on the inlet valve surfaces. It also takes into account the valve spring preload in the overall balance of forces moving the valve. Simulation of the valve motion was achieved by providing the solver with two user-defined functions. The plunger lift-time history was defined by the crank diameter and connecting rod length. This paper will demonstrate the feasibility and reasonable accuracy of the method adopted by comparison with experimental data.