scholarly journals A varying comprehensive hydropower coefficient for medium/long-term operation of a single reservoir

2020 ◽  
Vol 51 (4) ◽  
pp. 686-698
Author(s):  
Wenting Gong ◽  
Pan Liu ◽  
Lei Cheng ◽  
He Li ◽  
Zhikai Yang
Keyword(s):  
Big Data ◽  
Hydropower Plant ◽  
Simulation Accuracy ◽  
K Value ◽  
Term Operation ◽  
Water Power ◽  
Hydropower Plants ◽  
Water Head ◽  
Study Results

Abstract In medium/long-term reservoir operation, the hydropower output is calculated from k × q × h, where q is the power discharge, h is the water head, and k is the comprehensive hydropower coefficient. k indicates the conversion efficiency from water power to electricity, however, it is standard practice to use a constant k. We developed a novel method to derive the varying k based on observed big data. The operational frequencies of different units for time (multiple periods) and space (multiple units) were accounted based on the observed big data from each unit, and then weights were obtained. Finally, k was derived by integrating the efficiency curves (hill charts) of the different units with their weights. The Three Gorges Project, China, was selected for a case study. Results indicated that: (1) the varying k value can improve hydropower simulation accuracy, (2) simulations using 10-day intervals have a higher accuracy for hydropower calculation than daily and monthly scales, (3) the evaluation of hydropower plant benefits is sensitive to k, and there is potential for producing more hydropower. These findings are highly relevant to the operation of hydropower plants and to the evaluation of medium/long-term hydropower generation for a hydropower plant.

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.

scholarly journals Optimization Model for the Long-Term Operation of an Interprovincial Hydropower Plant Incorporating Peak Shaving Demands

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4804
Author(s):  
Rui Cao ◽  
Jianjian Shen ◽  
Chuntian Cheng ◽  
Jian Wang
Keyword(s):  
Power Generation ◽  
Optimization Model ◽  
Hydropower Plant ◽  
Mixed Integer ◽  
Short Term ◽  
Long Distance ◽  
Peak Shaving ◽  
Term Operation ◽  
Proposed Model

The increasing peak-to-valley load difference in China pose a challenge to long-distance and large-capacity hydropower transmission via high-voltage direct current (HVDC) lines. Considering the peak shaving demands of load centers, an optimization model that maximizes the expected power generation revenue is proposed here for the long-term operation of an interprovincial hydropower plant. A simulation-based method was utilized to explore the relationships between long-term power generation and short-term peak shaving revenue in the model. This method generated representative daily load scenarios via cluster analysis and approximated the real-time electricity price of each load profile with the time-of-use price strategy. A mixed-integer linear programming model with HVDC transmission constraints was then established to obtain moving average (MA) price curves that bridged two time-coupled operations. The MA price curves were finally incorporated into the long-term optimization model to determine monthly generation schedules, and the inflow uncertainty was addressed by discretized inflow scenarios. The proposed model was evaluated based on the operation of the Xiluodu hydropower system in China during the drawdown season. The results revealed a trade-off between long-term energy production and short-term peak shaving revenue, and they demonstrated the revenue potential of interprovincial hydropower transmission while meeting peak shaving demands. A comparison with other long-term optimization methods demonstrated the effectiveness and reliability of the proposed model in maximizing power generation revenue.

Stormwater Management Ponds and Wetlands Sediment Maintenance

2000 ◽  
Vol 35 (3) ◽  
pp. 525-540 ◽  
Author(s):  
Edward I. Graham ◽  
Jian H. Lei
Keyword(s):  
Stormwater Management ◽  
Term Operation ◽  
Study Results

Abstract Effective long-term operation of Stormwater management ponds/wetlands requires maintenance. This study has evaluated many aspects related to such maintenance needs with respect to removal, methods of removal and disposal of removed sediments. This paper summarizes the study results that should be useful to owners/operators responsible for the maintenance of Stormwater management ponds/wetlands.

scholarly journals The Benefits of Variable Speed Operation in Hydropower Plants Driven by Francis Turbines

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3719 ◽  
Author(s):  
Edson Bortoni ◽  
Zulcy de Souza ◽  
Augusto Viana ◽  
Helcio Villa-Nova ◽  
Ângelo Rezek ◽  
...  
Keyword(s):  
Climate Change ◽  
Economic Feasibility ◽  
Hydropower Plant ◽  
Variable Speed ◽  
Constant Frequency ◽  
Hydropower Plants ◽  
Water Head ◽  
Frequency Grid ◽  
Theoretical Analyses ◽  
Hydro Turbines

Climate change and environmental degradation has resulted in a reduction in water inflow at hydropower plants, as well as a decrease in reservoir levels. Existing hydropower plants suffer from water head reduction, mainly with decrease in efficiency of energy conversion in hydro turbines. This paper showcases the benefits of operations with variable speed in existing hydropower plants, when working at a lower water head than the rated one. Theoretical analyses and tests were performed in a special constructed laboratorial setup aiming at evaluating the amount of efficiency recovery with variable speed operation. Connection alternatives for a constant frequency grid and applications of the learned concepts in an existent hydropower plant are presented. The investigations were applied to the Furnas hydropower plant. The results point out that economic feasibility of the application can be achieved.

Influence of Sand Concentration on Variation Characteristics of Aquifer Parameters under Groundwater Source Heat Pump Long-Term Operation

2013 ◽  
Vol 689 ◽  
pp. 551-555
Author(s):  
Song Qing Wang ◽  
Shi Jing He
Keyword(s):  
Heat Pump ◽  
Simulation Method ◽  
Confined Water ◽  
Seepage Velocity ◽  
Term Operation ◽  
Aquifer Parameters ◽  
Water Head ◽  
Variation Characteristics ◽  
Groundwater Source

The influence of sand concentration on variation characteristics of aquifer parameters, under groundwater source heat pump long-term operation, is theoretically analyzed through numerical simulation method. The present studies show that the sand concentration obviously affects the variations of the porosity and hydraulic conductivity, however, the variation of confined water head is affected inconspicuously. The variations of aquifer parameters are also related with the seepage velocity.

scholarly journals Forecasting the durability of public transport bus bodies depending on operating conditions

2021 ◽  
Vol 4 (1(112)) ◽  
pp. 26-33
Author(s):  
Dmytro Ruban ◽  
Lubomir Kraynyk ◽  
Hanna Ruban ◽  
Andrii Sosyk ◽  
Andriy Shcherbyna ◽  
...  
Keyword(s):  
Public Transport ◽  
Operating Conditions ◽  
The Body ◽  
Body Frame ◽  
Operational Conditions ◽  
Term Operation ◽  
Study Results ◽  
Depth Study ◽  
Bus Body

This paper addresses the issue related to forecasting the durability indicators of public transport buses under operational conditions. It has been established that when buses are operated to transport passengers the bus bodies wear at different intensities. During operation, the strength of the body frame weakens under the influence of corrosion in combination with sites of fatigue destruction. As it was established, the intensity of corrosion of the bus body depends on the number of residents in the city where the bus is operated. The earlier established dependences were taken into consideration; the current study has identified two conditional variants of corrosion evolution based on the number of inhabitants: up to 1 million and exceeding 1 million. The expediency of repairs and their impact on the bus passive safety has been analyzed. It was found that the elements of the body frame, without external characteristic damage, no longer meet the specified conditions of strength as a result of sign-alternating loads and during long-term operation. Determining the durability of the bus body was made possible through the construction of a mathematical model. The model’s adequacy was confirmed by road tests of the bus. The devised model describes the movement of the bus over a road surface with different micro profiles, with different corrosion penetration, different loading by passengers, and bus speeds. It was established that the reason for the evolution of structural corrosion is the influence of salt mixtures preventing the icing of roads, as well as ignoring the washing of buses after such trips. It is recommended to use new software for the in-depth study into this issue addressing the combination of various factors of destruction: cyclic loads at variable bus speeds and the corrosion progress. The study results could make it possible to predict a life cycle of the body frame under factors that correspond to actual operating conditions.

scholarly journals Monitoring of Elastic Deformations of the Hydraulic Structure Gabcíkovo

2021 ◽  
Vol 906 (1) ◽  
pp. 012106
Author(s):  
Juraj Škvarka ◽  
Emilia Bednárová ◽  
Ivan Slávik ◽  
Monika Takácová
Keyword(s):  
Hydraulic Structure ◽  
Load Condition ◽  
Hydropower Plant ◽  
Measuring Instruments ◽  
Limit Values ◽  
Term Operation ◽  
Navigation Lock ◽  
The Right ◽  
The Impact

Abstract The settlement and its calculations and monitoring are among the main factors influencing the structure and operability of hydraulic structures. Our paper focuses on the hydraulic structure Gabcíkovo which consists of the hydropower plant with an installed capacity of 720 MW and two navigation locks to ensure international ship transportation. Conventional geodetic methods of classical or very precise leveling with state-of-the-art measuring instruments are currently used to monitor deformations on navigation locks of hydraulic structure Gabcíkovo. In their subsoil, there are gravelly sediments to a depth of about 400 m. Under the gravel sediments, there are Neogene clays and silts. From the beginning of construction, deformations are measured on all structures using special tachymetric devices to monitor the elastic displacements. The obtained measured values are then processed in time dependences and compared with the limit values. During the current almost 30-year operation of the navigation locks, filling and emptying cycles, loading and unloading of the subsoil can be counted in the tens of thousands. The impact of the long-term operation, but especially the current innovation and modernization of navigation locks, aimed at increasing the safety and intensity of transport brings new knowledge and experiences. During the implementation of required improvement related to this project, the right navigation lock is empty for more than a year. The created technical conditions made it possible to monitor the influence of long-term unloading on the subsoil on the vertical displacements in detail. This unusual load condition is a motivation to present the results of measurements in the presented paper.

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