MS Candidate
Aman Kapali (aman.kapali@ku.edu.np)
Supervisors / Advisors
Prof. Hari Prasad Neopane
Dr. Sailesh Chitrakar
Objectives
1. Develop a hydro turbine test rig suitable for sediment erosion testing at Turbine Testing Lab
2. Study the erosion on guide vanes of Francis turbine and blade of Cross flow turbine using the sediment erosion test rig
3. Perform design optimization of the vanes for better sediment handling using computational and experimental approaches
Summary
Hydro- abrasive erosion is a complex phenomenon caused by the dynamic impact of solid particles against the solid surface. Erosion is dependent on particle size, speed, concentration, angle of attack and behavior of the eroded material. The effect of each of these parameters is difficult to study, as the hydro- abrasive erosion behavior and results vary with the nature of the test performed. However, it is necessary to take all these factors into consideration for predicting the erosion in hydro turbine components. Extensive experimental results have been reported from the past studies from different erosion tests performed. Considering the complexities of developing a setup that replicate the actual erosion behavior of turbine, a test rig is being developed in TTL premises that closely meet the operating requirements.
This set up consists of three distinct discrete systems: Sediment injection system, Sediment Separation system and Flexible Test rig System. Sediment is introduced into the system using peristaltic pump with inbuilt variable frequency drive (VFD) and pulse dampener for varying flow rate of Water-sediment Mixture. This mixture after passing through runner is separated by use of two hydro cyclones in parallel mode. Easy and flexible test rig system is taken into consideration for solving the issues of setting up and dismantling each time after the purpose of project has been achieved. Further, for optimal design of erosion test set up that can closely meet the actual operating requirements, slurry pump especially designed for handling abrasive is employed over normal pumps for generation of necessary flow and head in the experimental rig. Moreover, the use of pressure tank can mitigate the limited use of setup by providing a wide range of head and steady flow at the turbine’s inlet. Thus, this set up developed is expected to be used to predict the erosion behavior and quantity the erosion rate of guide vanes of Francis turbine and blade of cross flow turbine under varying operating conditions. Also, this set up will be used to perform erosion experiment on different turbine materials to develop empirical erosion model under similar operating conditions.
Funded by
UGC (Nepal)