热-压形变对超高压水压泵柱塞副间隙泄漏的影响

Influence of thermal-pressure deformation on clearance leakage of piston pair in ultra-high pressure water pump

柱塞副间隙的泄漏是影响柱塞泵容积效率的主要因素,超高压工况下柱塞副微米间隙的热-压形变不可忽略.利用流-固-热耦合方法,建立柱塞副压形变主导模型和热-压耦合形变模型,对单边间隙高度5μm的柱塞副二维轴对称模型中的压差流动进行仿真计算.结果表明:当柱塞副入口压力为110 MPa时,在间隙入口受压形变占主导,单边间隙增大4μm以上,在间隙出口热形变占主导,单边间隙减小1.1μm;压形变主导模型计算所得柱塞副间隙泄漏量为柱塞副无形变时的4倍;热-压耦合形变模型计算所得柱塞副间隙泄漏量是柱塞副无形变时的1.3倍.研究结果为准确预测超高压水压泵柱塞副的间隙泄漏流量提供方法.

The leakage of the clearance of the piston pair is the main factor affecting the volumetric efficiency of the piston pump,and the thermal-pressure coupling deformation of the micron clearance of the piston pair can not be ignored under ultra-high pressure.Based on the thermal-fluid-structure coupling method,the dominant pressure deformation model and the thermo-compression coupling deformation model were established to simulate the differential pressure flow in the two-dimensional axisymmetric model of the piston pair with 5μm unilateral clearance height.The results show that when the inlet pressure of the piston pair is 110 MPa,the compressive deformation is dominant at the inlet of the clearance,and the unilateral clearance increases by more than 4μm,while the thermal deformation is dominant at the outlet of the clearance,and the unilateral clearance decreases by 1.1μm.The clearance leakage of the piston pair is 4 times as much as that of the piston pair without deformation under the model dominated by compression deformation.The clearance leakage of the piston pair calculated by thermal-pressure coupling deformation model is 1.3 times that of the piston pair without deformation.The research results provide a method for accurately predicting the clearance leakage flow of the piston pair of the ultra-high pressure water pump.