Sediment Erosion in Head Cover Pressure Balancing Pipe – A Case Study of Chameliya Hydroelectric Power Station (CHEPS)
Date
2022-09
Authors
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Publisher
I.O.E. Pulchowk Campus
Abstract
The Chameliya Hydropower Plant, located in the Darchula district of Far-Western Province in Nepal has been used as a case study to investigate the erosion caused by sediment in the head cover pressure balancing pipe which has been a significant erosion issue since commissioning. Analyses of erosion have been done by a field study and Computational Fluid Dynamics (CFD) based erosion modeling using a commercial CFD code ANSYS Fluent and the results were compared qualitatively and quantitatively. The sediment concentration (ppm), Particle size distribution (PSD) and Mineral content of the sediment samples were tested. The maximum concentration was found to be 5308.70 ppm on 2021, July 4 and the minimum was 420.20 ppm on 2021, May 3. According to PSD analysis, 90% of the particles (by weight) fall in the range of 0.01 mm to 0.1 mm in the dry month and 0.01 mm to 0.5 mm in the wet month. Despite weather variations, the mineral composition of the silt was seen to be stable, with an average of 70.8% of the minerals being harder than the material of the pressure balance pipe (i.e. Steel SS304). Erosion rate density at respective points (where the thickness were measured) was calculated experimentally as well as using CFD simulation. The location of erosion-prone area was found to be the same as the real-life scenario,
Description
The Chameliya Hydropower Plant, located in the Darchula district of Far-Western Province in Nepal has been used as a case study to investigate the erosion caused by sediment in the head cover pressure balancing pipe which has been a significant erosion issue since commissioning.
Keywords
Sediment, Erosion, Hydroelectric Power