scholarly journals Effects of the maximum flow ramping rates on the long-term operation decisions of a hydropower plant

2014 ◽  
pp. 514-519 ◽  
Author(s):  
I. Guisández ◽  
J.I. Pérez-Díaz ◽  
J.R. Wilhelmi
Keyword(s):  
Maximum Flow ◽  
Hydropower Plant ◽  
Term Operation

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.

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 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.

Analysis of crystallite size changes in a hematite and magnetite formed on steel used in the power idustry

2017 ◽  
Vol 1 (21) ◽  
pp. 65-73
Author(s):  
Monika Gwoździk
Keyword(s):  
Elevated Temperature ◽  
Oxide Layer ◽  
Cross Section ◽  
X Ray ◽  
Term Operation ◽  
Diffraction Line Profile ◽  
Crystallite Sizes ◽  
Scherrer Formula ◽  
Pipe Outlet

The paper presents results of studies on the crystallite sizes of oxide layer formed during a long-term operation on 10CrMo9-10 steel at an elevated temperature (T = 545° C, t = 200,000 h). This value was determined by a method based on analysis of the diffraction line profile, according to a Scherrer formula. The oxide layer was studied on a surface and a cross-section at the outer and inner site on the pipe outlet, at the fire and counter-fire wall of the tube. X-ray studies were carried out on the surface of a tube, then the layer’s surface was polished and the diffraction measurements repeated to reveal differences in the originated oxides layer.

Retention and expression of recombinant plasmids in suspended and biofilm-bound bacteria degrading trichloroethene (TCE)

1997 ◽  
Vol 36 (10) ◽  
pp. 1-8 ◽  
Author(s):  
James D. Bryers ◽  
Robert R. Sharp
Keyword(s):  
Biofilm Reactor ◽  
Bacterial Biofilm ◽  
Laboratory Evaluation ◽  
Recombinant Bacteria ◽  
Suitable Host ◽  
Term Operation ◽  
Open Environment ◽  
Recombinant Microorganisms ◽  
Extracellular Polymer

Exposure of plasmid recombinant microorganisms to an open environment, either inadvertently or intentionally, requires research into those fundamental processes that govern plasmid retention, transfer and expression. In the open environment, a majority of the microbial activity occurs associated with an interface, within thin biological layers consisting of cells and their insoluble extracellular polymer, layers known as biofilms. Current toxic wastewater or wastegas treatment reactors exploit bacterial biofilm systems for certain system operating advantages. Using recombinant bacteria within a biofilm reactor to degrade xenobiotic wastes requires finding a suitable host to harbor and express the desired plasmid phenotype. Suitable host characteristics include: the ability to produce copious amounts of biofilm, resistance to waste-related injury and toxicity, and the ability to retain and express the desired plasmid during long term operation. This paper reports on a laboratory evaluation of factors governing plasmid retention and the expression of trichloroethene (TCE) degradative capacity in both suspended and biofilm cultures.

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