具有内压缩过程的潜油螺杆泵设计与数值模拟

Design and numerical simulation of progressive cavity pump with internal compression process

传统的全金属单螺杆泵的螺杆转子与定子在结构上没有内压缩过程,在用于井下潜油时需要较长的螺杆。为减小潜油螺杆泵的长度,提高其在油井中的通过性,提出一种具有内压缩过程且具有卸压通道的变啮合间隙全金属单螺杆泵。推导变啮合间隙全金属单螺杆泵截面的型线方程,研究啮合间隙的变化规律,得到新型变啮合间隙全金属单螺杆泵的设计方法。采用数值模拟研究新型变啮合间隙全金属单螺杆泵的工作性能,得到其内部压力场和速度场的分布情况,并将其与传统的等啮合间隙结构进行对比。结果表明在其他参数均相同的前提下,所提出的新型变啮合间隙单螺杆泵的长度较小,轴向泄漏速度较小,其综合性能得到了提高。

The screw rotor and stator of the conventional all-metal progressive cavity pump(AMPCP)do not experience an internal compression process,so that the screw length is relatively long during the downhole oil.In order to reduce the length of the AMPCP and improve its passability in the oil well,an AMPCP with a variable meshing gap,whose functions include internal compression processes and pressure relief channels,was proposed in this study.The profile equations of the cross section of the AMPCP with a variable meshing gap were deduced.Then the variation law of the meshing gap was studied,and the design method of the new screw was obtained.Furthermore,the working performance of the new AMPCP was studied by numerical simulations,and then the distributions on the internal pressure field and velocity field were obtained,compared with the conventional AMPCP with equal meshing gaps.The results show that the length of the proposed new AMPCP is relatively small and its axial leakage speed is also smaller when the other parameters are kept the same.Therefore,its comprehensive performance is improved.