轴面流道类型对径向直叶片水轮机的性能影响

Influence on Performance of Radial Straight Blade Hydraulic Turbine in Different Meridional Flow Channel

针对径向直叶片水轮机轴面流道做混流式和全径向式布置时对性能的影响进行研究。首先建立径向直叶片水轮机的理论模型,然后基于两种不同类型的轴面流道进行转轮设计,最后通过数值仿真对其外特性和内部流场进行分析对比。研究表明,两种方案均能适应超小流量和较宽的水头变化范围,采用混流式流道方案时最优数值预测效率为81.4%,较全径向式流道方案偏大1.8%,并具有较高的过流能力。经试验检验混流式流道方案的最优效率约74.2%,基本满足超小流量余能回收的需要。研究成果为超小流量余能回收水轮机的设计提供参考。

In this paper,the influence on performance of radial straight blade hydraulic turbine is studied with radial meridional flow channel and mixed-flow meridional flow channel.Firstly,the theoretical models are suggested for radial straight blade hydraulic turbine.Secondly,runners are designed based on two different types of meridional flow channels.Finally,the numerical simulation is carried out for different schemes,while the performance and flow field are analyzed and compared.Results show that the two different schemes adapt to ultra-small discharge and head with large fluctuation.Moreover,the best numerical predicted efficiency is 81.4%for radial straight blade hydraulic turbine with the mixed-flow meridional flow channel,which is 1.8%more than the radial meridional flow channel.Meanwhile,with a larger conveyance capacity,the optimal efficiency is verified for the hydraulic turbine with mixed-flow meridional channel,and it can meet the needs of hydraulic energy recovery with ultra-small discharge.The conclusions serve as a reference in the design of hydraulic energy recovery turbine.