全金属螺杆泵定转子配合优化及特性试验研究

Optimization of Rotor and Stator Assembly of All-metal Positive Displacement Pump

为确定全金属螺杆泵定转子的最优间隙值,针对全金属螺杆泵定转子间隙配合的特点,分别采用有限元热力学分析方法和大涡模拟(Large eddy simulation,LES)模型,分析了金属螺杆泵内流动特性及温度、黏度对全金属螺杆泵定转子配合间隙的影响规律。根据优化分析结果,确定全金属螺杆泵定转子最优配合间隙区间为0.1~0.3 mm,并试制全金属螺杆泵样机进行试验。模拟结果表明:当转速相同时,黏度小于0.05 Pa·s的介质,泵效受间隙值影响效果显著,间隙值达到0.6 mm时,泵效降为0%;当介质黏度大于0.50 Pa·s时,间隙值对泵效的影响明显变小;介质黏度和转速是泵效的主要影响因素,提高转速可以改善泵效,但介质黏度对泵效的影响更为显著。现场测试结果表明:研制的全金属螺杆泵使用性能满足设计要求,其运转特性与室内试验结果基本一致,运行过程平稳可靠,泵效基本无变化。研究结果可为全金属螺杆泵的现场应用提供指导。

In order to determine the optimal clearance of all-metal positive displacement pump rotor and sta-tor ,based on the clearance fit feature, a finite element method and the large eddy simulation （ LES） model were used to analyze the effect of flow characteristics, fluid temperature and fluid viscosity on the rotor and stator clear-ance fit. According to the results of optimization analysis, the optimum clearance of all-metal positive displacement pump stator and rotor is 0. 1 ~ 0. 3 mm. An all-metal positive displacement pump prototype is produced and tested. The simulation results show that, given the same RPM, the effect of clearance was significant when the fluid viscos-ity was less than 0. 05 Pa ？ s. The pump efficiency was reduced to 0% under the clearance of 0. 6 mm. The effect of the clearance value on pump efficiency was significantly reduced when the viscosity of the medium was higher than 0. 50 Pa ？ s. Medium viscosity and RPM are the main factors affecting pump efficiency. Increasing RPM can improve pump efficiency, but medium viscosity has more significant effect on pump efficiency. The field test results show that the performance of the new developed all-metal positive displacement pump meets the design require-ments ,with its operating characteristics basically the same as the indoor test results. The operation process is stable and reliable, and the pump efficiency basically remains unchanged. The results could provide guidance for the field application of all-metal positive displacement pump.