正反转双转轮水轮机水力性能研究

Research on Hydraulic Performance of Twin Runners with Counter Rotation for Hydro-turbine

研究用于低水头的反转双转轮、双转子小型水力发电设备,探讨反转双转轮的基本原理与水轮机转轮的水力特性,确认了在流量一定的运转工况时反转前转轮转速与正转后转轮转速相等条件下可以得到最高效率、且出力为两转轮之和(单转轮的2倍)。通过模型实验,确认了正反转两转轮的水力性能基本满足一般的相似准则,可以进行实际转轮设计时的换算。

In order to urgently cope with the global greenhouse effect,it is necessary to explore the utilization of the clean renewable hydro-energy even with the low heads.To do so,this paper presents,in lieu of the conventional bulb turbines,a new type of the self-compensating-torque and the reduced size of the double-stage axial hydro-turbine having twin runners with counter-rotation;the negative-rotating front-runner drives the outer-rotor of new type generator,while the positive-rotating rear-runner drives the inner-rotor.The fundamental principle of the new turbine as well as the hydraulic performances of the double-stage runners were as following: under the constant discharge,when the negative rotating speed of the front-runner coincides with the positive rotating speed of the rear-runner,the hydraulic efficiency reaches maximum,and the total turbine output power is twice of the respective runners.By confirming experimentally that the general similarity law can be applicable to the hydraulic performance of the new turbine,it is possible to apply the results to the design of the protopype machines.