Experimental Investigations on Sediment Erosion of Pump As Turbine

Abstract

v newlineAbstract newlineOne of the biggest problems with hydro turbines is silt erosion, especially in rivers with lots newlineof sediment particles in the flow. The hard particles present in water such as quartz, cause newlinethe erosion of different turbine parts, failure of mechanical components, and sometimes even newlinethe shutdown of the hydro plant. In many hydropower plants, sediment basins are installed newlineto trap silt particles going to the turbine but due to their limitations and high concentration of newlinesmall-size silt particles, it is found impossible to eliminate the silt erosion. Several newlineresearchers have developed empirical correlations for the prediction of erosive wear of hydro newlineturbines by taking softer materials like Aluminum and Brass to get the erosion in a shorter newlinetime. The correlations developed can not be used in practice as the materials examined for newlinethe impeller blades were different from the actual impeller material. There are no direct newlinecorrelations available for reaction turbines and PAT setups to relate erosion with operating newlineparameters. Pump as turbine (PAT) is one of the most affordable and environmental friendly newlinesolutions for electrification in rural areas. These plants are usually run-of-river or hill-based, newlineand during monsoon, they experience a lot of unsettled sediments. The detrimental effects newlinecaused by hard particles lead to downtime, repairs, and/or the necessity of replacement, which newlinehave an adverse impact on power generation. newlineIn this study, an effort has been made to experimentally evaluate the silt erosion of the PAT. newlineThe novelty of the study is to use the same material (SS304) for the specimens used for the newlineanalysis as well as for the impeller. The experiments were performed with three silt sizes of newline100-350 and#956;m, 350-700 and#956;m, and 700-1000 and#956;m; with three different silt concentrations of newline0.75%, 1%, and 1.25% for the duration of 18 hrs, 36 hrs, and 54 hrs. An empirical correlation newlinewas established for the assessment of normalized wear of the PAT impeller in terms of silt newlinesize, concentration, and operating time based o