scholarly journals Researches of the kharanorsk reservoir ecosystem according to the outcomes of the plankton primary production assessment

Author(s):  

This article presents the results of the assessment of production and destruction processes in the ecosystem of the Kharanorsk reservoir-cooler, used as a cooling pond of the Kharanorsk hydroelectric power station. The content of dissolved oxygen in the water of the reservoir is ubject to seasonal dynamics corresponding to biochemical processes occurring in the reservoir. In spring and autumn, the concentration of dissolved oxygen is in the range from 12.6 to 14.2 mg / L. We attribute the decrease in oxygen content in the summer month to 9.6 mg / L with an increase in air temperature and with the thermal effect of thermal power plants, which in total lead to an intensification of the processes of biochemical decomposition of organic and oxidation of mineral substances. High production capabilities of the ecosystem in both the central and littoral zones were found in July in the surface horizons of the water column (3.53 mgO2 / L – littoral; 3.92 mgO2 / L – center). The formation of organic matter in the direction “surface horizon - bottom layers” of the water column in the central zone decreases due to a decrease in the transparency of the water column. The cessation of the production of organic matter by phytoplankton in the bottom layers of the littoral zone we associate with the competitive relationship of bottom organisms in the use of nutrients. It has been established that the rate of daily production increases from April to July and begins to fall in October, but remains high relative to spring indicators in both the central and littoral zones of the reservoir. The studies are necessary for subsequent environmental monitoring studies, as well as for making managerial decisions to maintain the sustainability of the reservoir ecosystem.

2021 ◽  
pp. 67-74
Author(s):  
O. N. CHERNYH ◽  
◽  
A. V. BURLACHENKO ◽  
V. V. VOLSHANIK ◽  
U. H. UMARU HAMANJODA

The results of the assessment and analysis of the operating modes of the power complex with the constructive and technological combination of hydraulic power plants (HPPs) with solar power plants (SFEU) in the presence of seasonal or daily regulation in the environmental hydro system are presented. The aspects of the operation of a hydroelectric power station with non-self-regulating derivation are considered in detail: when working in a load schedule with a maximum power equal to the installed one, and when the average daily power along the watercourse is approaching the provided one. It was found that in the first case, the influence of the SPEU regime on the joint work with the hydroelectric power station is to move a part of the load graph of the hydroelectric power plant with the maximum power to the base part of the schedule. In the second case, the influence of the SPEU mode consists in changing the variable part of the load graph, but the HPP, in contrast to the first case, retains its position in the load graph of the power system. The mode of operation of the hydroelectric power station becomes more uniform and at the same time, a smaller volume of the daily regulation basin (DRB) is required. For the example considered, the maximum power of the hydroelectric power station during the day increased from 50 MW to 54 MW. It has been revealed that even with the production of SPEU in 18% of the daily production of hydroelectric power plants, the volume of DRB is required approximately two times less. As a result, it is possible to increase the operating head at the hydroelectric power station and obtain the corresponding effect on power and electricity generation.


Author(s):  
Petro Lezhnyuk ◽  
Iryna Hunko ◽  
Juliya Malogulko ◽  
Iryna Kotylko ◽  
Lіudmyla Krot

Urgency of the research. Current trends of distributed generation development in Ukraine indicate a rapid generation in-crease from renewable energy plants. Most developed countries gradually refuse from the fossil fuels use and invest more and more to the “green” energy. Therefore, there is a need for a detailed study of the operation conditions of distributed energy sources due to their instability, as well as the processes that arise in distribution electric networks with diverse types of distributed energy sources. Target setting. In the producing process of power energy by distributed energy sources due to the increase in their num-ber, there are situations where several renewable sources of energy operate to only one system of buses. Thus, such distributive networks acquire the features of a local power system, which complicates the control process of such systems, and also there is a problem with the electricity supply of consumers. Actual scientific researches and issues analysis. The analysis of publications suggests that in literature more attention is paid to studying the operating modes of solar power plants, or small hydroelectric power plants. However, almost no attention was paid to the study of their cooperation work. Uninvestigated parts of general matters defining. Only a few works are devoted to the study of the cooperation of the diverce sources of distributed energy sources in the local electrical systems. That is why, their impact on power distribution networks and on the grid in general has not been studied extensively. The research objective. In this article was considered the influence of asynchronous generators on small hydroelectric power plants on the operation modes of distribution electrical networks, and were investigated the processes that are occurring in local power systems with different types of distributed energy sources. The statement of basic materials. Based on the research results, was developed a computer model of a such system in the PS CAD software environment. Two solar stations and one small hydroelectric power station with an asynchronous generator were connected to the power supply. It was shown the simulation of two modes of operation: a joint operation of a small hydroelectric power station, two solar power stations and a power supply center; a joint operation of a small hydroelectric pow-er plant, two solar power stations and a power supply disconnected. Conclusions. As a result of computer simulation, it is shown that by switching on a small hydroelectric power plant with an asynchronous generator in the case of an emergency shutdown of centralized power supply, it is possible to restore the work of solar power plants, and thus partially or completely restore the power supply of consumers.


2021 ◽  
Vol 11 (2) ◽  
pp. 62-66
Author(s):  
Sergey V. EVDOKIMOV ◽  
Alexey A. ROMANOV ◽  
Boris G. IVANOV

The experience of operation of surface emergency gates in ice-breaking conditions at a number of hydroelectric power plants has shown the insuffi cient eff ectiveness of the methods used to combat freezing of structures. The rules for technical operation of spillway dam gates in winter provide for heating of structures by slots, threshold and skin in conjunction with measures to maintain mines before construction. However, measures to heat gates and build mines are not always suffi ciently justifi ed and justifi ed. In order to obtain full-scale data and scientifi c information for the development of recommendations on operating and accounting modes during design, full-scale studies of stresses and defl ections in the load-bearing elements of the watershed gate of the hydroelectric power station were carried out. This article presents the results of fi eld studies in comparison with calculated values. As a result of the studies, information on the static operation of fl at gates in winter conditions is obtained, which is of theoretical and practical interest. The materials can be used to clarify technical operation rules and to clarify regulatory documents for the design of hydromechanical equipment at hydroelectric power stations.


2019 ◽  
Vol 114 ◽  
pp. 01006
Author(s):  
Gleb Mayorov ◽  
Valery Stennikov ◽  
Eugene Barakhtenko

The current technological infrastructure in the electricity, heat, cold, and gas supply, as a rule, is formed and controlled separately by local systems and tasks. The traditionally considered energy systems unite large energy sources, such as hydroelectric power station, combined heat and power plants, boiler plants, and electric and pipeline networks distributed over a large area. New trends in the energy sector necessitate a revision of the principles of construction of energy systems and the creation of integrated energy supply systems. Combining separate different types of systems of different levels into a single integrated system with many coordinated elements can contribute to the implementation of new functionality, the use of more advanced technologies in operation and the active participation of consumers with distributed generation in the energy supply process. For the study of integrated energy supply systems it is proposed to use a multiagent approach, which is one of the promising areas of research for complex systems. This approach is used in many subject areas to study systems that include many elements with complex behavior. Such systems include integrated energy supply systems. The solution of the problem on the basis of the agent approach is developed by a multitude of interrelated agents.


2015 ◽  
Vol 5 (4) ◽  
pp. 86-92 ◽  
Author(s):  
Mikhail Ivanovich BALZANNIKOV

Considered run-of-river hydropower plants (HPP). Notes the importance of technical-economic calculations in the justifi cation of large water-conducting elements of the path these types of HPP. The methodology of economic substantiation of the expediency of increasing the length of the draft tube. Using the technique of the calculations for lowpressure hydroelectric run-of-river type. The results of the analysis of the influence of the operating conditions of the hydroelectric power station on basic geometrical parameters of draft tube.


Author(s):  
K. A. Gemueva

The article examines the relationship between China’s exports to African countries and the implementation of energy projects by Chinese companies. The structure of Chinese exports to Africa and trends in the development of bilateral trade is analyzed. Key factors explaining the close correlation between exports and project implementation are: first, the significant volume of tied financing provided by Chinese banks for the construction of energy infrastructure in African countries, second, the need of these countries to purchase a lot of high-tech equipment in the absence of relevant industries on their territory. The dynamics of supplies of specialized equipment from China used for the construction of various types of power plants - hydroelectric power plants, thermal power plants, wind power plants and solar power plants - is considered in detail. The article provides examples of energy projects of Chinese companies in African countries, for which the supply of equipment is directly found in the imports of the respective countries from China. The tendency for Chinese companies to open production facilities in African countries, in particular cement plants and a photovoltaic modules plant, is noted. The author concludes that the African market remains extremely promising for the implementation of energy projects and the sale of relevant Chinese products despite some negative factors.


2021 ◽  
pp. 57-65
Author(s):  
O. N. CHERNYH ◽  
◽  
A. V. BURLACHENKO ◽  
V. V. VOLSHANIK

The issues of solving modern problems related to meeting the energy needs of environmental hydraulic engineering are considered. The problem of improving the methodological basis for choosing the optimal arrangement of elements of photovoltaic devices (SPEU) on the blocks of the dam building of hydroelectric power plants (HPP) of 4 main types is formulated. The graphical dependences of the estimation of the power ratio of the combined SPEU and HPP on the diameter of the turbine wheel are analyzed. As a result of the analysis of the influence of the location of the transformer on the possibility of placing the SPEU on the buildings of the hydroelectric power station, it was revealed that in order to increase the adaptability of the revitalized even large hydro system with a separate building of the hydroelectric power station, it is preferable to place power transformers from the downstream side. It is noted that according to the results of the schematic study for the medium-pressure hydroelectric complex Lagdo in the north of Cameroon, the placement of solar cells will provide an additional 6.95% of the capacity of the operating hydroelectric power station.


2021 ◽  
Author(s):  
Elena Shirkova ◽  
Eduard Shirkov

"The article presents an overview of the technical, economic, and environmental arguments in favour of wider use of the gigantic energy potential of sea tides to solve the most important climate problem today – the reduction of anthropogenic pollution of the Earth's atmosphere with carbon dioxide. The main idea of the considered solution is the replacement of carbon fuels for thermal power plants and transport with ""green"" hydrogen. The production of such hydrogen is carried out by electrolysis using the energy of carbon–free renewable sources. Tidal hydroelectric power plants are the cheapest, largest and most economically safe electricity supplier for the production of green hydrogen today. Until now, this direction of the energy sector has not become widespread due to the high capital intensity, as well as due to the geographic remoteness of the places where tidal energy is concentrated from large centres of electricity consumption. The explosive growth in global hydrogen demand in recent years alleviates the problem of very expensive transport and large losses in long distance transmission of electricity. Hydrogen can be transported without loss and relatively cheaply by pipelines and sea tankers over unlimited distances. The use of the energy of the highest tides and flow in the Pacific Ocean for the production of ""green"" hydrogen is proposed in the revived project of construction of the world's largest Penzhinsk Tidal Hydroelectric Power Plant (the Sea of Okhotsk’ north–east, Russia)."


Hydrobiologia ◽  
2021 ◽  
Author(s):  
Antonio Petruzziello ◽  
Luca Bonacina ◽  
Francesca Marazzi ◽  
Silvia Zaupa ◽  
Valeria Mezzanotte ◽  
...  

AbstractAlpine and pre-alpine lotic ecosystems are often remote and not affected by humans, which makes them some of the world’s most pristine ecosystems. However, their status is often altered by the presence of reservoirs that are built to fulfill agricultural needs and hydroelectric demands. These reservoirs also disrupt stream continuity and alter the magnitude, timing, and frequency of natural flows. The present work assessed how high-altitude reservoirs affect the riverine ecosystems focusing on the following: (i) the macroinvertebrate communities, (ii) the breakdown of organic matter, and (iii) the thermal regime. Stretches altered by high-altitude reservoirs had the best conditions for most macroinvertebrate families due to a more stable flow conditions. The breakdown rate of coarse particulate organic matter was not affected by high-altitude reservoirs but its availability was higher in altered compared to pristine stretches. The presence of hydroelectric power plants modified the stream thermal regime. Reservoirs mitigate the atmospheric influence on stream water temperature while run of the river plants strengthen it in the diverted stretches. Where both these alterations were present, the thermal regime of the stream was more similar to the natural ones compared to stretches subjected to only one kind of alteration. This research showed how river impoundment alters the structure of macroinvertebrate communities and the function of the downstream lotic ecosystems and can provide the basis to correctly guide management strategies for lotic ecosystems affected by hydrological alterations.


Author(s):  
Konstantin S. Fediy ◽  
Sergey A. Vstovskiy ◽  
Igor S. Fedorchenko ◽  
Evgeny A. Spirin

The disadvantage of hydroelectric dams is the flooding and a material breach of the ecology of the region, therefore the use of such hydroelectric power station is reasonable when no alternative method of providing the required power. In this regard, in most cases, it is advisable to use free-flow microelectric power plants. Free-threaded micro hydropower plants constitute a power unit mounted in the flow of the river. The main difference between free-flow microelectric power plants and dams is the use of kinetic energy of the flow, rather than potential. This makes it possible to eliminate the need for earthworks and the construction of additional hydraulic structures. Free-threaded micro hydropower plants can be grouped, forming a cascade of micro hydro. In order to increase the reliability of free-flow microelectric power plants, the design tends to use low-speed generators with rotation speeds from 140 to 650 rpm, which can significantly simplify or completely eliminate the transmission mechanism


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