PERFORMANCE EVALUATION OF PELTON TURBINE USING CFD

Abstract

Performance evaluation of different components of hydro power station is considered to be a challenging task. As such, there are various components which come in contact with the water, but turbine is the most critical component because it has a considerable influence on the overall performance as well as life of any hydropower project. For performance evaluation of hydro turbines, flow is required to be analyzed critically as highly complex flow condition occur and it is generally turbulent and three dimensional in nature. Performance of a turbine can be evaluated experimentally but it is tedious, time consuming and costly. Pelton turbine is suitable for high head schemes and it is used for small hydro power plants in hilly areas where it is sometimes not affordable to get the performance evaluation experimentally. It is therefore, the performance can be evaluated by using CFD. CFD is a tool for analyzing the flow inside various hydraulic components under different conditions. It is cost effective and less time consuming process. It gives precise and accurate results. Keeping this in view, the present work is aimed to carry out a CFD analysis in order to evaluate the performance of a Pelton turbine. In the present dissertation work, the performance of a 1.5 MW Pelton turbine under 200 m head and 0.85 m3/s discharge is evaluated. The computational modeling is done in GAMBIT software, using the dimensions as calculated from the above data. The jet diameter is 132 mm and the jet ratio is assumed to be as I 0.This geometry is imported in FLUENT software to analyze the fluid flow. Torque is evaluated for different load conditions using the standard k-E turbulence model. Therefore, efficiency is calculated at different loads to obtain the operating characteristic curve of the Pelton turbine. The efficiency of the turbine is evaluated as 80.80%, 85.81%, 89.3 1% and 86.27% at 60%, 80%, 100% and 110% load respectively. The complete algorithm of the process is described and presented