Date of Graduation

2016

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Mechanical and Aerospace Engineering

Committee Chair

Andrew C Nix

Committee Co-Chair

Kenneth H Means

Committee Member

Gregory J Thompson

Abstract

The goal of this project was to measure the performance of two micro-hydro Turgo Impulse Turbine Impellers. In 2014, Hydropower accounted for 6% of total electric power produced and 48% of electricity produced by renewable sources in the United States. Micro-hydro power is an established, robust, and versatile technology that can help society produce electric power without the emission of greenhouse gases and with minimal environmental impact. Competition from other renewable energy sources is causing the operational efficiency and power production of micro-hydro turbines to become increasingly important. This competition puts pressure on manufacturers to improve the quality of their turbine designs and manufacturing methods. Computational fluid dynamics (CFD), combined with numerical methods and increased computing power, have become more widely used tools in the past several decades for design improvement. However, empirically derived performance data is still needed to validate modeling improvements and support further development of hydropower technology. Two impellers were chosen for study because they were used in an operational turbine system that the experiments were modeled after. The first impeller was designed and partially manufactured by Hartvigsen Hydro and assembled by Preston Machine, Inc. The second impeller had been in operation in the turbine system for several years and showed signs of wear. The blades on the two impellers were shaped very differently due to having completely different manufacturers. A test setup was designed and constructed to measure the overall efficiency and power output of both impellers. Two types of performance experiments were conducted. The first experiment determined the most efficient setting for the inlet nozzles which are used to increase the kinetic energy of the water prior to impinging on the turbine impeller. The second experiment measured the efficiency and power output of each impeller while varying the flow rate and shaft speed for each of two impellers. The results were analyzed and displayed as three dimensional maps for graphical interpretation of turbine performance as conditions were varied. The experiments indicate that the new impeller (impeller A) operated most efficiently with a peak efficiency 84.6% (with mechanical losses excluded). The older impeller (impeller B) reached a peak efficiency of 74.8%. Both impellers produced approximately the same amount of shaft power (28.6 hp with mechanical losses included) at their peak operating points. The experiments indicated that both turbines were sensitive to varying conditions and properly managing those conditions is necessary to obtain reliable and efficient energy output over a long operational lifetime.

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