水泵进口预旋及涡流强度测试新技术

设计不良的泵站进水建筑物 ,在不带泵运行的情况下 ,也会引起水泵进口水流预旋和吸水管内涡流 ,改变水泵的进水条件 ,恶化水泵的能量特性和汽蚀特性。提出了观测泵进口水流预旋和测量泵进口涡流强度的新技术。通过丝线流场显示技术 ,观察喇叭口进口水流的预旋 ;采用旋度计测定水泵吸水管内涡角的大小 ,可定性和定量地评判水泵进水设计 ,优化进水设计方案 ,确保水泵有良好的进水条件 ,提高水泵装置运行的安全性和可靠性。

A New Technique of Measuring Pre-swirl and Swirl Flow Intensity inside Pump Suction Pipe

Incorrect designed intake structure of a pumping station may result in pre swirl in the flow entering the pump and swirl in suction pipe even under no pump operation, which shall change flow condition, and affect adversely both pump performance and cavitation characteristics. A new method is put forward in this paper for investigating pre swirl in flow entering the pump intake and for measuring swirl in the suction pipe. By means of tuft flow visualization method pre swirl in flow entering the suction bell is observed, and swirl angles of flow in the pump suction pipe are measured with a swirl meter. Evaluation of pump intake design can be made qualitatively and quantitatively, and schemes of intake design can be optimized as well. With the help of the new technique, a favorable flow condition can be created for a pump and the operation safety and reliabilities of a pumping station can be improved obviously.