贯流泵叶轮与灯泡体相干机理与优化匹配研究

Water Resources in China is uneven spatial distribution，and the South-to-North Water Diversion Project is a major strategic measure for the fundamental solution of the problem of critical shortage of water resources in the northern area of our country. Bulb tubular pump is especially suitable for large discharge and low lift head pumping stations with the characteristics of small hydraulic loss and high efficiency, which is the periferred pump type of South-to-North Water Diversion East Route Project. However, the internal structures of bulb tubular pump system are complex, and the interaction between passage components makes the characteristics of internal flow be complex. To improve the hydraulic performance, the key is to deeply understand the internal flow characteristics and the interaction mechanism between the passage components. In this project, the basic scientific research on the internal flow characteristics and interaction mechanism of impeller and bulb unit is carried on which is to bulb tubular pump system as the research object. The detailed contents conclude: the theoretical analysis and calculation on the internal flow pattern of bulb tubular pump system and the interaction law between the impeller and bulb unit; obtain a large objective and reliable experimental data through 3D laser doppler velocimetry(LDV) measurement, and establish the optimized matching forecast model of impeller and bulb unit. This project aims to reveal the interaction mechanism of impeller and bulb unit of bulb tubular pump system, and establish the optimized matching model, which can lay a technical foundation for improving and perfecting the bulb tubular pump system optimization design theory and further improving the tubular pump performance.

中国水资源空间分布不均，北方地区水资源严重短缺，南水北调工程是解决该问题的重大举措。灯泡贯流泵适用于扬程低、流量大的泵站，具有水力损失小、装置效率高等特点，是南水北调东线工程中低扬程泵站的优选泵型。然而，灯泡贯流泵装置内部结构复杂，其过流部件之间的干涉作用使得其内部流动特性复杂。要进一步提高水力性能，关键是要深刻认识其内部流动特征和过流部件之间相干机理。本项目以灯泡贯流泵装置为研究对象，对其内部流动特征及叶轮和灯泡体的相干机理进行基础科学研究。具体内容包括：理论分析与计算灯泡贯流泵装置内部水流流态、叶轮与灯泡体之间水力相干的规律；通过三维LDV流场测试，获得大量客观、可靠的实验数据，建立叶轮与灯泡体优化匹配的预测模型。本项目旨在揭示灯泡贯流泵装置内叶轮与灯泡体相干机理，建立两者的优化匹配模型，为改进和完善灯泡贯流泵装置的优化设计理论和进一步提高贯流泵性能奠定技术基础。

本项目以灯泡贯流泵装置为研究对象，采用数值模拟、模型试验和流场测试相结合的方法对其内部流动特征及叶轮和灯泡体的相干机理进行深入的研究。首先，采用CFD方法对后置灯泡贯流泵装置进行了全流道三维数值模拟，获得了泵装置在不同工况下运行时的内部流动特征，并将预测的水力性能与模型试验结果进行了对比，两者基本吻合。其次，计算了灯泡贯流泵装置各部分的水力损失，结果显示导叶体和灯泡段在水力损失中所占的比重比较大，针对这一情况重点研究了导叶的设计参数、灯泡段的进人孔和灯泡体形状以及灯泡体支撑形式对装置性能的影响。通过多方案优化设计，探求了叶轮与导叶及灯泡体的优化匹配关系，并对导叶和灯泡体部分的过流部件结构进行优化，提高了泵装置效率。最后，为了验证数值模拟研究和理论分析的合理性，建立了一套用于激光流场测试的小型透明灯泡贯流泵试验台进行实验研究，通过模型试验获得了模型灯泡贯流泵装置的性能曲线，采用三维LDV流场测试技术获得了灯泡贯流泵内部流动数据，对CFD计算结果进行了验证，并提出了一种基于LDV测试贯流泵内部流场的测试方法。