“Condition Monitoring of hydraulic turbines exposed to sediment erosion”- Prajwal Sapkota, PhD candidate, Turbine Testing Lab (TTL), Kathmandu University

Prajwal Sapkota is a PhD candidate at the Department of Mechanical Engineering at Kathmandu University (KU), Nepal. He is writing his PhD thesis on a project within HydroCen (Norwegian Research Centre for Hydropower Technology): FranSed (Francis Turbine for Sediment Laden Waters) at Turbine Testing Lab of KU. KU is one of the three partners of FranSed project.

“I joined team FranSed in January 2019 as a researcher and almost after a year in December 2019, I defended my PhD proposal on "Condition Monitoring of hydraulic turbines exposed to sediment erosion" before the Research Committee of School of Engineering, Kathmandu University”, says Sapkota.

Learned the process of designing hydro-mechanical components

Sapkota completed his Bachelor’s Degree in Mechanical Engineering from KU in 2015.

“As a part of Bachelor's degree, I started exploring hydropower sector as an intern in a hydro consulting company of Nepal: Nirvana Tech. Pvt. Ltd. where I learned the process of designing hydro-mechanical components. In the meantime, I completed my Master's degree in 2018 from the Department of Mechanical Engineering at Institute of Engineering-Pulchowk Campus (Tribhuvan University).”

In 2018, Sapkota started working as a Mechanical engineer at a hydro-mechanical company of Nepal i.e. Cream Hydel Pvt. Ltd. located in Butwal.

“Cream Hydel is one of the leading companies of Nepal in the context of design, manufacturing, installation, testing & commissioning of hydro-mechanical works and repair works of turbine equipment. During my tenure at Cream Hydel, I gained both managerial and technical experiences related to hydro-mechanical works.”

He also served as a part time lecturer at Kumari Engineering College located in Kathmandu.

Gained interest in sediment erosion in turbines

After visiting different sediment affected hydropower plants in Nepal, during his academic as well as professional career, Sapkota started gaining interest in sediment erosion in turbines.

“I have been keenly following the research conducted at Turbine Testing Lab since the beginning of the lab, which coincidently was inaugurated the same year I joined Kathmandu University for my Bachelor’s degree.”

His passion for research and skills in instrumentation as well as programming led him to be a researcher under FranSed project.

Model testing of turbine of a reference power plant at Turbine Testing Lab (TTL): WP4 of FranSed Project

FranSed is a multi-dimensional project that involves NTNU, KU and IIT Roorkee and project activities are being carried out simultaneously. One of the objectives of WP 4 of FranSed project is to test a model turbine of reference power plants i.e. Bhilangana Power Plant, India and Jhimruk Power Plant, Nepal at TTL following the guidelines and procedures defined by IEC. The project expects to reduce the erosion problem of turbines by accommodating few changes in design and with the use of optimization techniques.  At the same time, TTL is in the process of standardization of model testing and calibration facilities to meet IEC 60193 guidelines.

“I am currently involved in different aspects of the project. I have been working to develop the energy scenarios that could predict energy demands of Nepal. I have been a part of standardization of the testing procedures at TTL. Furthermore, I am frequently involved in operation and development of calibration and testing programs using LabView.”

“I had worked on data acquisition and realtime performance monitoring program for 14 kW simplified guide vane-less Francis Turbine. I have been working on improving my skills and competence in instrumentation, data acquisition, data processing, automation, operation and control of different sensors and devices at TTL. I expect to test the optimized reference model turbine in accordance with IEC guidelines and instrumentation at TTL for FranSed project in near future.”

Sapkota's PhD journey at Kathmandu University in his own words

"First of all, I would like to thank my family, friends and entire team at Turbine Testing Lab, including professors from the Department of Mechanical Engineering, Kathmandu University for this opportunity."

Condition monitoring is the process of predicting or detecting faults on machine components or devices, and is one of the newest areas of research for TTL. Sediment erosion is one of the biggest challenges for hydropower sector in entire Himalayan geography as it largely affects the performance of turbines by eroding various components.

“My PhD will primarily focus on correlating the sediment erosion with other measured parameters in several ways so that erosion could possibly be detected using realtime monitoring system.  The outcome of this PhD is expected to benefit the FranSed project, in the context of analyzing the pulsations and structural integrity introduced due to variable speed operations of Francis turbines.”