25-08-2017, 09:32 PM
studied the various factors and uncertainties involved in pelton jet which account for decreasing the efficiency of pelton turbine then validated the seco
25-08-2017, 09:32 PM
21-09-2017, 10:43 AM
The Pelton turbine has been subject to a varying degree of interest in research since the technology's debut more than a century ago. Despite their antiquity, there are gaps in the knowledge of the flow mechanisms that effect the flow through the turbine. A Pelton turbine has been designed at the NTNU Waterpower Laboratory. This has been done in connection with a PhD. project focused on flow in Pelton turbine tanks. The design of the turbine has been carried out using internal knowledge, in addition to some comments from a turbine producer. To describe the geometry, multiple B'ezier curves were used and the design strategy aimed to give a smooth and continuous gradient along the main flow directions in the cube. The turbine has been designed for the operating conditions of the Pelton test platform installed in Waterpower Laboratory, which is a horizontal single-jet test platform with a jet diameter (ds) of 35 mm. The diameter (D) of the guide was set at 513 mm and the width (W) of a hub 114 mm, resulting in a D / W ratio of 4.5. The turbine has been manufactured in aluminum and the turbine has been tested for efficiency and visual inspection during operation at a height of 70 m. The turbine did not work as expected and the maximum efficiency was 77.75%. The low efficiency is mainly caused by a large amount of water coming out of the bucket through the lip and thus transferring near zero of its energy to the shaft. The reason for the great loss of the lip is discussed and two possible causes are found; the jet is located too close to the lip, and the inner surface of the hub does not move the water away from the lip. The turbine geometry and all data from both measurements and simulations will be available upon request in an effort to increase the amount of data available on Pelton turbines.