基于流体力学泄漏模型的螺杆泵泄漏机理分析

Leakage Mechanism of Screw Pump Based on Leakage Model in Fluid Mechanics

针对螺杆泵筒壁间隙、啮合间隙等决定螺杆泵性能的关键间隙设计问题,在研究螺杆各项间隙构成原理的基础上,运用流体力学间隙泄漏理论,建立泵腔间隙泄漏压差流和剪切流模型,分别分析螺杆泵筒壁间隙和啮合间隙的泄漏量,得到螺杆泵不同间隙泄漏的表达式。以主动螺杆2头、从动螺杆3头的双螺杆泵为例,通过理论计算与试验对比分析了螺杆转速、压差对泵泄露的作用机理,揭示了螺杆转速、泵进出口压差对螺杆泵流量特性及容积效率特性的影响规律,从而完善了螺杆泵转子设计理论,提升了螺杆泵输送性能。

Clearance leakage is the main cause of pump leakage.Aiming at the design and control of the key clearance,which determines the performance of screw pump such as clearance of barrel wall and meshing area,the model of differential pressure flow and shear flow of clearance leakage in pump cavity is established.The mathematical expressions of leakage from different clearance are obtained by analyzing the clearance leakage of barrel wall and meshing area.The influence of the rotation speed and pressure difference between inlet and outlet on flow characteristics and volumetric efficiency characteristics of screw pump is revealed by theoretical calculation and experimental analysis of twin screw pump.Based on these results,the rotor design theory of the screw pump as well as the performance of the screw pump can be improved.