scholarly journals Assessment of the effect of shapes of a shaft intake structure using the PIV method

2021 ◽  
Vol 1209 (1) ◽  
pp. 012072
Author(s):  
L Bytčanková
Keyword(s):  
Flow Velocity ◽  
Vertical Section ◽  
Structure Design ◽  
Hydropower Plant ◽  
Horizontal Distance ◽  
Negative Effects ◽  
Small Hydropower ◽  
Horizontal Section ◽  
Intake Structure ◽  
Distribution Of Flow

Abstract The construction of shaft intake structures in Slovakia has increased. The shaft intake structures overcome significant vertical height over short horizontal distance. In their front horizontal section, the water flows with free surface, then in the vertical section the flow changes its direction and character to a pressurized flow. The flow of water in these shaft intake structures is therefore very complicated. A hydraulically suitable design of the intake structure is associated with achieving the required parameters of the small hydropower plant (SHPP), but due to the reduction of project costs, the shapes of shaft intake structures of SHPP are often not correctly hydraulically designed. One of the important aspects is the distribution of flow velocity of these intake structures. Uneven distribution of flow velocity causes negative effects on turbine performance. Therefore, the investigation of the effects of shaft intake structure design on flow velocity distribution has been realized. The velocity field at a shaft intake of a small hydropower plant was investigated on a physical model in a hydraulic laboratory using the PIV (Particle Image Velocimetry) method. The PIV measurements were realized for different shaft heights and proved negative effects of the design on the flow homogeneity in the turbine intake.

scholarly journals Evaluation of the flow velocity distribution in the intake structure of a small hydropower plant

2021 ◽  
Vol 1203 (2) ◽  
pp. 022102
Author(s):  
Lucia Bytčanková ◽  
Ján Rumann ◽  
Peter Dušička
Keyword(s):  
Velocity Distribution ◽  
Flow Velocity ◽  
Negative Impact ◽  
Current Situation ◽  
Hydropower Plant ◽  
Small Hydropower ◽  
Hydropower Plants ◽  
Intake Structure ◽  
Distribution Of Flow ◽  
Flow Velocities

Abstract Intake structures are an important part of small hydropower plants, which affect the water flow, turbine operation and total power of power plant. The flow quality is significantly influenced by the flow homogeneity in the intakes, as the inhomogeneous flow velocity distribution has a negative impact to the operation of the hydropower plants, such as uneven load on the mechanical parts which leads to decrease in efficiency and faster aging of turbine parts. The paper describes the flow assessment in the intake structures of a low-pressure small hydropower plant (the Stará Ľubovňa small hydropower plant) with respect to the flow homogeneity. The River2D, 2D numerical modelling software, has been used for evaluation of flow in the intakes. Flow simulations for the current state of operation have been modelled. In assessing the current situation of intake structure, scenarios were modelled. The boundary conditions were changed to approximate the various variants of hydropower plant operation. The simulations proved the negative impact of the construction solution for the flow conditions in the intakes. This appears mostly in profiles of coarse racks and screenings where is a significant unequal distribution of flow and significant deviation in flow velocities from the recommended values. The simulations results were evaluated in turbine intake profiles (profile of screenings), where the distribution of flow velocities was evaluated. The flow velocities in this profile were compared with the average flow velocity in the turbine intake profile. In order to optimize the velocity distribution in the intake structure, the modification of the intake shapes has been proposed. The subject of the proposal was to improve flow parameters. Simulations were created for the modification that were subsequently reviewed. The modification was compared to the current situation of the intakes.

Analyzing the impact of intake structure on the flow at low pressure SHPP

2021 ◽  
Author(s):  
Lucia Bytčanková ◽  
Ján Rumann ◽  
Peter Dušička
Keyword(s):  
Velocity Distribution ◽  
Flow Velocity ◽  
Hydropower Plant ◽  
Small Hydropower ◽  
Hydropower Plants ◽  
Low Head ◽  
Structural Parts ◽  
Numerical Flow Modeling ◽  
Intake Structure ◽  
The Impact

AbstractThe structural parts of intake structures directly affect the flow velocity distribution in the turbine intake of small hydropower plants, where inhomogeneous flow leads to uneven load of the turbine units causing operational problems. A 2D numerical flow modeling was used for investigations of the flow in an intake structure of a low-head small hydropower plant. The effects of shape changes of the intake structure on the flow velocity distribution in the turbine intakes were investigated and assessed proving significant effect of the shapes of the intake structure on the flow homogeneity in turbine intakes.

Research on the Relationship of Flow Velocity and Particles’ Separation in Cyclone

2012 ◽  
Vol 479-481 ◽  
pp. 2529-2532
Author(s):  
Ying Zhang ◽  
Zhen Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Structure Design ◽  
Rotating Flow ◽  
Separation Performance ◽  
Simulation Results ◽  
Relationship Of ◽  
The Relationship ◽  
Distribution Of Flow

This paper mainly focuses on the numerical simulation of flow velocity aiming to obtain the velocity distribution of flow in the cyclone. The authors took advantage of RSM turbulence model of software FLUENT to calculate the velocity distribution. Relationship between particles separation and double-layer rotating flow can be obtained based on the simulation results, which can also provide basis for the improvement of structure design and separation performance.

scholarly journals Development of a Hydropower Turbine Using Seawater from a Fish Farm

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 266
Author(s):  
Md Rakibuzzaman ◽  
Sang-Ho Suh ◽  
Hyoung-Ho Kim ◽  
Youngtae Ryu ◽  
Kyung Yup Kim
Keyword(s):  
Power Plants ◽  
Guide Vane ◽  
Cross Flow ◽  
Synchronous Generator ◽  
Fish Farm ◽  
Hydropower Plant ◽  
Fish Farms ◽  
Data Simulation ◽  
Small Hydropower ◽  
Hydropower Plants

Discharge water from fish farms is a clean, renewable, and abundant energy source that has been used to obtain renewable energy via small hydropower plants. Small hydropower plants may be installed at offshore fish farms where suitable water is obtained throughout the year. It is necessary to meet the challenges of developing small hydropower systems, including sustainability and turbine efficiency. The main objective of this study was to investigate the possibility of constructing a small hydropower plant and develop 100 kW class propeller-type turbines in a fish farm with a permanent magnet synchronous generator (PMSG). The turbine was optimized using a computer simulation, and an experiment was conducted to obtain performance data. Simulation results were then validated with experimental results. Results revealed that streamlining the designed shape of the guide vane reduced the flow separation and improved the efficiency of the turbine. Optimizing the shape of the runner vane decreased the flow rate, reducing the water power and increasing the efficiency by about 5.57%. Also, results revealed that tubular or cross-flow turbines could be suitable for use in fish farm power plants, and the generator used should be waterproofed to avoid exposure to seawater.

scholarly journals Fishways as Downstream Routes in Small Hydropower Plants: Experiences with a Potamodromous Cyprinid

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1041
Author(s):  
Francisco Javier Sanz-Ronda ◽  
Juan Francisco Fuentes-Pérez ◽  
Ana García-Vega ◽  
Francisco Javier Bravo-Córdoba
Keyword(s):  
General Assumption ◽  
Downstream Migration ◽  
Life Cycles ◽  
Hydropower Plant ◽  
Small Hydropower ◽  
Pit Tag ◽  
Safe Alternative ◽  
Hydropower Plants ◽  
Longitudinal Connectivity ◽  
Alternative Routes

Fish need to move upstream and downstream through rivers to complete their life cycles. Despite the fact that fishways are the most commonly applied solution to recover longitudinal connectivity, they are not considered viable for downstream migration. Therefore, alternative facilities are recommended to facilitate downstream migration. However, a few recent studies have disagreed with this general assumption, showing the potential for bidirectional movements. This study advances our understanding of the potential of fishways for downstream migration by studying their efficiency in a run-of-the-river hydropower plant in the Duero River (Spain). To achieve this, downstream movements of the Iberian barbel (n = 299) were monitored in a stepped fishway for two years with passive integrated transponder (PIT)-tag technology, considering the effect of fish origin and release zone. The results showed that 24.9% of barbels descended through the fishway, with the origin and release zone affecting the fishway location. In addition, downstream movements were observed throughout the whole year, except in winter. The study concludes that, under specific scenarios, fishways could act as safe alternative routes for downstream migration.

scholarly journals Fine-scale multiannual survey of benthic invertebrates in a glacier-fed stream used for hydropower generation

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Alberto Scotti ◽  
Roberta Bottarin
Keyword(s):  
Research Programme ◽  
Eastern Alps ◽  
Hydropower Plant ◽  
Research Network ◽  
Small Hydropower ◽  
Hydropower Plants ◽  
Before And After ◽  
Long Term Ecological Research ◽  
Research Facilities

AbstractThe present dataset contains information about aquatic macroinvertebrates and environmental variables collected before and after the implementation of a small “run-of-river” hydropower plant on the Saldur stream, a glacier-fed stream located in the Italian Central-Eastern Alps. Between 2015 and 2019, with two sampling events per year, we collected and identified 34,836 organisms in 6 sampling sites located within a 6 km stretch of the stream. Given the current boom of the hydropower sector worldwide, and the growing contribution of small hydropower plants to energy production, data here included may represent an important – and long advocated – baseline to assess the effects that these kinds of powerplants have on the riverine ecosystem. Moreover, since the Saldur stream is part of the International Long Term Ecological Research network, this dataset also constitutes part of the data gathered within this research programme. All samples are preserved at Eurac Research facilities.

Survival of fish passing downstream at a small hydropower facility

2018 ◽  
Vol 69 (12) ◽  
pp. 1870 ◽  
Author(s):  
Stephen V. Amaral ◽  
Benjamin S. Coleman ◽  
Jenna L. Rackovan ◽  
Kelly Withers ◽  
Benjamin Mater
Keyword(s):  
Mississippi River ◽  
River Flow ◽  
Survival Rates ◽  
Fish Populations ◽  
Negative Effects ◽  
Small Hydropower ◽  
The Usa ◽  
Pass Through ◽  
Hydro Project ◽  
Total Project

Hydropower dams can negatively affect upstream and downstream migratory fish populations in many ways, such as blocking access to upstream habitats and causing injuries or mortality during downstream passage. For downstream passage at projects in the USA, federal regulators and agencies responsible for oversight of hydropower facilities typically require assessment studies and mitigation to address negative effects, with a primary goal of minimising fish impingement and turbine entrainment and mortality. So as to assess the effects of downstream passage of fish populations at a unique, small hydro project on the Mississippi River, impingement and entrainment rates, Oberymeyer gate passage, spillway gate passage, turbine survival, and total downstream passage survival were estimated. It was determined that 85% of fish passing downstream at the project would be small enough to pass through the bar spacing of the trash racks and 15% would be physically excluded. When 55% of river flow enters the turbine intake channel, the total project survival rates were estimated to be 77.3% with an Obermeyer gate bypass rate of 10 and 96.6% with a gate bypass rate of 90%. Therefore, any effects on local fish populations resulting from the operation of the project are expected to be negligible and inconsequential on the basis of expected survival rates for the range and probability of river flows occurring at the project.

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