Next Article in Journal
Suspended-Sediment Distribution Patterns in Tide-Dominated Estuaries on the Eastern Amazon Coast: Geomorphic Controls of Turbidity-Maxima Formation
Next Article in Special Issue
Efficiency Assessment for Rehabilitated Francis Turbines Using URANS Simulations
Previous Article in Journal
Observations of Tidal Flat Sedimentation within a Native and an Exotic Spartina Species
Previous Article in Special Issue
Velocity Structure of Density Currents Propagating over Rough Beds
Article

Operation of Norwegian Hydropower Plants and Its Effect on Block Fall Events in Unlined Pressure Tunnels and Shafts

1
Department of Geoscience and Petroleum, Norwegian University of Science and Technology (NTNU), Petroleumsteknisk Senter, F 410, Valgrinda, S.P Andersens Vei 15a, 7031 Trondheim, Norway
2
Department of Civil and Environmental Engineering, Norwegian University of Science and Technology (NTNU), Vassbygget, 322, Valgrinda, S. P. Andersens veg 5, 7031 Trondheim, Norway
*
Author to whom correspondence should be addressed.
Academic Editors: Jochen Aberle and Robert Boes
Water 2021, 13(11), 1567; https://doi.org/10.3390/w13111567
Received: 30 April 2021 / Revised: 26 May 2021 / Accepted: 30 May 2021 / Published: 1 June 2021
(This article belongs to the Special Issue Advances and Challenges in Hydropower)
The main objective of this study is to investigate the effect of hydropower plant operation on the long-term stability of unlined pressure tunnels of hydropower plants in Norway. The authors analyzed the past production data of some hydropower plants to find out the number of starts/stops and the frequency and magnitude of load changes. The study demonstrates that an average of 200–400 start/stop events are occurring per turbine per year for the analyzed period, with an increasing trend. Currently, 150–200 large load changes per turbine smaller than 50 MW are occurring every year, and this is expected to increase by 30–45% between 2025 and 2040 for one of the studied power plants. Most importantly, the monitored pressure transients and pore pressure response in the rock mass during real-time operation at Roskrepp power plant are presented. A new method is proposed to calculate and quantify the hydraulic impact (HI) of pressure transients on rock joints and the effect of duration of shutdown/opening, which is found to be the most dominant parameter affecting the magnitude. The results show that faster shutdown sequences cause unnecessary stress in rock mass surrounding pressure tunnel. The hydraulic impact (HI) can be more than 10 times higher when the shutdown duration is reduced by 50 percent. The study recommends that duration of normal shutdowns/openings in hydropower plants should be slower so that hydraulic impacts on the rock joints are reduced and cyclic hydraulic fatigue is delayed, prolonging the lifetime of unlined pressure tunnels and shafts. View Full-Text
Keywords: hydropower; unlined pressure tunnels; hydraulic transients; hydraulic impact; long-term stability; cyclic fatigue; block falls hydropower; unlined pressure tunnels; hydraulic transients; hydraulic impact; long-term stability; cyclic fatigue; block falls
Show Figures

Figure 1

MDPI and ACS Style

Neupane, B.; Vereide, K.; Panthi, K.K. Operation of Norwegian Hydropower Plants and Its Effect on Block Fall Events in Unlined Pressure Tunnels and Shafts. Water 2021, 13, 1567. https://doi.org/10.3390/w13111567

AMA Style

Neupane B, Vereide K, Panthi KK. Operation of Norwegian Hydropower Plants and Its Effect on Block Fall Events in Unlined Pressure Tunnels and Shafts. Water. 2021; 13(11):1567. https://doi.org/10.3390/w13111567

Chicago/Turabian Style

Neupane, Bibek, Kaspar Vereide, and Krishna K. Panthi 2021. "Operation of Norwegian Hydropower Plants and Its Effect on Block Fall Events in Unlined Pressure Tunnels and Shafts" Water 13, no. 11: 1567. https://doi.org/10.3390/w13111567

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop