Analysis of Operating Performance Parameters of the Internal Twin Screw Pump

Abstract

In response to the challenge of unclear characteristics within the internal flow field and operational performance of internal twin screw pumps, this study employs computational fluid dynamics to investigate the internal flow field variations during operation. Numerical simulation models are established for both internal twin screw pumps and conventional single screw pumps. Through three-dimensional transient dynamic mesh simulations, a comparative analysis of the internal flow field of these two screw pump types leads to the observation that the internal twin screw pump exhibits a remarkable advantage in volumetric efficiency and superior sealing performance compared to the single screw pump. Furthermore, examining the impact of parameters such as internal and external rotor clearances, medium viscosity, inner rotor speed, and single-stage pressure difference on the outlet flow and volumetric efficiency of the internal twin screw pump reveals overarching trends and underlying mechanisms. The findings indicate that the outlet flow of the internal twin screw pump diminishes with increasing pressure difference, and the influence of pressure difference on flow reduction is mitigated by higher medium viscosity. It is deduced that internal twin screw pumps are more suitable for application in medium or high-viscosity oil wells. With volumetric efficiency being modulated through prudent adjustments in speed. Conversely, internal twin screw pump leakage rises with augmented outer rotor clearance and reduced medium viscosity. These research outcomes hold significant implications for enhancing performance and refining the structural design of internal twin screw pumps in practical applications.