Performance Characteristics of Spiral Water Wheel and Optimal Structure to Micro-hydropower System

Abstract

A spiral water wheel had been invented in Toyama Prefecture in the twentieth century. Unlike conventional water wheels, the wheel can be operated, for example, in low water head and levels. In this study, we tried to generate electricity by employing the wheel at an agricultural irrigation channel.
Through the results of performance experiment as an example, we found that the spiral water wheel was operated most efficiently when it was placed parallel to the channel bed which gradient was approximately 25 degrees. It was also found that the micro hydropower system developed here was suitable for electric generation at the point of sudden drop of an irrigation channel. The build-in blades of the micro hydropower system had a spiral shape form; therefore, the blades could catch kinematic and potential energy both without loss. The blades could convert water energy into electrical or mechanical energy efficiently even in a small channel.