STUDY OF EROSION MODELS OF IMPULSE TURBINES THROUGH STATISTICAL ANALYSIS

Abstract

Hydro turbine is the most important part of hydro power plant which converts the potential energy of water into mechanical energy. The presence of silt in water erodes the turbine material. Hydropower generation faces challenge in withdrawal of clean water from sand-laden rivers. This leads to silt erosion and further to unexpected shutdowns. Erosion of turbine decreases the performance of turbine, life of the turbine as well as loss of power generation. In the present study, erosion model correlations developed by various researchers are considered to get the erosion rate in hydro turbines operating under silt- laden water of river. These erosion model expressions contain the parameters (silt size, silt concentration, flow velocity and operating time) which causes erosion rate. These parameters values range are taken from the selected authors’ experiments. In the above selected range of parameters are used to get the normalized wear rate of turbines for Padhy and Saini, Khurana and Varun and Thakur et. al models. Based on the erosion values graphs are drawn for all three erosion models and their comparison shows that Khurana and Varun model gives lesser wear rate while Padhy and Saini gives moderate erosion rate. Further Padhy and Saini research experiment’s actual wear rate data taken as standard data on the basis of availability to do the statistical analysis of the selected erosion models. The above analysis result gives lesser standard deviation for Khurana and Varun model and for Thakur et. al, it is higher while for Padhy and Saini it is moderate. Therefore this study shows that Khurana and Varun erosion model is best suited to get the erosion rate of a hydro power plant