Operational Stability of a Hydropower Plant with a Pipe-Shaped Air-Cushion Surge Chamber

2020 ◽  
Author(s):  
Tingyu Xu ◽  
Jian Zhang ◽  
Sheng Chen ◽  
Wei He ◽  
xiaodong Yu ◽  
...  
Keyword(s):  
Volume Ratio ◽  
Operational Stability ◽  
Hydropower Plant ◽  
Water Volume ◽  
Stable Operation ◽  
Initial Water ◽  
Hydropower Plants ◽  
Small Load ◽  
Air Cushion ◽  
Horizontal Area

Abstract This paper theoretically analyzed the design and operating parameters of a pipe-shaped air-cushion surge chamber (PS-ACSC). A mathematical model for a small load disturbance in a hydropower plant containing the PS-ACSC was established to analyze the effects of the sensitivity of its initial horizontal area and the air-water volume ratio on the operational stability of the plant. The results showed that the PS-ACSC should occupy a critical horizontal area, and its initial water level and the initial air-water volume ratio should be within a certain range to ensure its own stable operation as well as that of the turbine units. The results of a case study showed that a hydropower plant containing the PS-ACSC is most stable when the initial air-water volume ratio ranges from 2.90:1 to 6.68:1. In addition, a hydropower plant containing the PS-ACSC delivers better performance than a horseshoe-shaped air-cushion surge chamber under the same conditions. This study contributes to the design and operational control of hydropower plants containing the PS-ACSC.

Study of The Influence of Different Variables on Clathrate Practical Applications in Phenol Removal

2020 ◽  
Vol 38 (9A) ◽  
pp. 1373-1383
Author(s):  
Riyadh S. AL- Mukhtar ◽  
Shurooq T. Remedhan ◽  
Marwa N. Hussin
Keyword(s):  
Crystal Structures ◽  
High Capacity ◽  
Volume Ratio ◽  
Constant Speed ◽  
Water Volume ◽  
Phenol Removal ◽  
Process Performance ◽  
Economic Costs ◽  
Practical Applications ◽  
Glass Cell

In this work, effluent wastewater treated by using cyclopentane-water Clathrate system to treat water contaminates with phenols at concentrations (300, 250, 200, 150, 100 and 50) ppm in order to investigate the capability of process performance. Clathrate or hydrate are strong crystal structures including water (host particles) and little particles (guest particles). The experiments were conducted at different cyclopentane-water volume ratios (1: 2 and 1: 4). The work was done in a 250 ml glass cell with an electric mixer at a constant speed of 280 cycles per minute. Phenol was highest removal percent at 300ppm at 1: 4volume ratio was (92.3%), while the lowest concentration at 50 ppm and 1: 2volume ratio was (55%). Yield and Enrich factor had the highest values at the lowest concentration 50ppm and 1:2 volume ratio were (85% and 2.42) respectively. The technique of the Clathrate proved that it has a high capacity in the separation and achieve high removal percentage compared to other methods at standard conditions when the pressure of 1 atmosphere and temperature higher than the degree of freezing water and less economic costs compared to other methods.

Role of micro-hydropower plants in socio-economic development of rural Afghanistan

2020 ◽  
pp. 1-7
Author(s):  
Mohammad Airaj Firdaws Sadiq ◽  
Najib Rahman Sabory ◽  
Mir Sayed Shah Danish ◽  
Tomonobu Senjyu
Keyword(s):  
Distribution System ◽  
Energy Demand ◽  
Economic Life ◽  
Hydropower Plant ◽  
Decent Work ◽  
Hydropower Plants ◽  
Development Goals ◽  
The Government ◽  
Decentralized Energy ◽  
Energy Options

Afghanistan hosts the Hindu Kush, an extension of the Himalaya mountains that act as water sources for five major rivers flowing through Afghanistan. Most of these rivers provide promise for the construction of water dams and installment of micro hydropower plants (MHP). Although civil war and political strife continue to threaten the country for more than four decades, the Afghan government introduced strategic plans for the development of the country. In 2016 Afghanistan introduced the Afghanistan National Peace and Development (ANPD) Framework at Brussels de-signed to support Afghanistan’s progress towards achieving the SDGs (Sustainable Development Goals). This study discussed the 7th Goal (ensuring access to affordable, reliable, and sustainable energy for all) and 8th Goal (promoting sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all) alignment in Afghanistan. The Afghan gov-ernment acknowledges its responsibility to provide electricity for all of its citizens, but this can only be achieved if the government can secure a reliable source of energy. Afghanistan’s mountainous terrain provides a challenge to build a central energy distribution system. Therefore this study looks for alternative solutions to the energy problems in Afghanistan and explores feasibility of micro-hydropower plant installations in remote areas. This study evaluated socio-economic im-pacts of micro-hydropower plants in the life of average residents. We focused on one example of a micro hydropower plant located in Parwan, conducted interviews with local residents, and gath-ered on-site data. The findings in this study can help policymakers to analyze the effects of devel-opment projects in the social and economic life of residents. It will encourage the government and hopefully the private sector to invest in decentralized energy options, while the country is facing an ever-growing energy demand.

The Numerical Modeling of Spherical Explosion in the Foam

2016 ◽  
Vol 11 (1) ◽  
pp. 60-65 ◽  
Author(s):  
R.Kh. Bolotnova ◽  
E.F. Gainullina
Keyword(s):  
Shock Wave ◽  
Numerical Modeling ◽  
Initial Pressure ◽  
Water Volume ◽  
Symmetric Model ◽  
Two Phase ◽  
Experimental Conditions ◽  
Initial Water ◽  
Aqueous Foam ◽  
Spherical Explosion

The spherical explosion propagation process in aqueous foam with the initial water volume content α10=0.0083 corresponding to the experimental conditions is analyzed numerically. The solution method is based on the one-dimensional two-temperature spherically symmetric model for two-phase gas-liquid mixture. The numerical simulation is built by the shock capturing method and movable Lagrangian grids. The amplitude and the width of the initial pressure pulse are found from the amount of experimental explosive energy. The numerical modeling results are compared to the real experiment. It’s shown, that the foam compression in the shock wave leads to the significant decrease in velocity and in amplitude of the shock wave.

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.

Effect of Synthesis Parameters on Size of the Biodegradable Poly (L-Lactide) (PLLA) Microspheres

2013 ◽  
Vol 858 ◽  
pp. 60-66 ◽  
Author(s):  
A.A. Hawari ◽  
C.Y. Tham ◽  
Zuratul Ain Abdul Hamid
Keyword(s):  
Electron Microscopy ◽  
Volume Ratio ◽  
Water Volume ◽  
Synthesis Parameters ◽  
Weight Variation ◽  
Infra Red ◽  
Biodegradable Poly ◽  
Evaporation Technique ◽  
Molecular Weight Variation ◽  
Scanning Electron

In this work, PLLA microspheres were prepared via emulsion solvent evaporation technique. Several synthesis parameters were studied to evaluate their effect on the size of PLLA microspheres. PLLA pallets before emulsion and PLLA microspheres surface chemistry after emulsion were determined using Fourier Transform Infra-red (FTIR). Results showed that PLLA pallets and microspheres FTIR obtained an identical spectrum. Microspheres size and surface morphology were determined using Scanning Electron Microscopy (SEM). In conclusion, the parameters that significantly affect the size of PLLA microspheres were PLLA concentration, DCM to water volume ratio, PVA concentration and stirring speed. PVA molecular weight variation showed no significant change in microspheres size.

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.

THREE-DIMENSIONAL SEEPAGE ANALYSIS OF A COAL REFUSE PILE RECLAMATION

2020 ◽  
Vol 9 (4) ◽  
pp. 44-66
Author(s):  
Iuri Lira Santos ◽  
Keyword(s):  
Mine Drainage ◽  
Characteristic Curve ◽  
Water Volume ◽  
Low Permeability ◽  
Initial Water Content ◽  
Initial Water ◽  
Seepage Analysis ◽  
Cover System ◽  
Coal Refuse ◽  
Refuse Pile

Abstract. A coal refuse pile located in Greenbrier County, West Virginia was studied to restrict generation of acid mine drainage through the use of a cap and cover system. This paper presents results of a finite element method seepage analysis on a proposed reclamation design. The proposed reclamation incorporates a cap and cover system with a 0.3-m thick surface vegetation cap layer over a 0.6-m thick low permeability layer. The low permeability layer is directly above the coal refuse. Unsaturated soil mechanics was utilized, adopting the Fredlund and Xing equation for soil-water characteristic curve (SWCC) estimation. SWCC fitting parameters were calculated using the Zapata and the Hernandez estimation techniques. Different precipitation events were used to evaluate seepage throughout the reclamation area and assess the effectiveness of the cap and cover system. A steep area (>4H:1V) and a flat area were considered. The water balance analysis showed a 50% to 88% reduction in water volume at the coal refuse layer and a reduction in the time for the refuse to return to initial water content due to the cap and cover system implementation. Moisture detainment was observed in the growth layer and is important for supporting vegetation persistence.

Dynamic Model of Rapeseed Oil Hydrolysis Reaction in Sub-Critical Water

2013 ◽  
Vol 860-863 ◽  
pp. 510-513 ◽  
Author(s):  
Yi Zhe Li ◽  
Hua Wang ◽  
Gui Rong Bao
Keyword(s):  
Activation Energy ◽  
Reaction Time ◽  
Dynamic Model ◽  
Rapeseed Oil ◽  
Reaction Order ◽  
Volume Ratio ◽  
Hydrolysis Reaction ◽  
Water Volume ◽  
Oil Water ◽  
Oil Hydrolysis

Experiments of Rapeseed Oil Hydrolysis Reaction in Sub-Critical Water (250-300°C, 5-60min) are Conducted in this Paper. Results Show that the Best Conditions for Rapeseed Oil Hydrolysis are Reaction Temperature 290°C, Oil-Water Volume Ratio 1:3, Reaction Time 40min, and Conversion Rate 98.9%. Meanwhile, Kinetic Analysis of this Hydrolysis Reaction is Presented. we Learn that Hydrolysis Reaction Order is 0.7778, Activation Energy is 55.34kJ/mol and the Dynamic Model is .

scholarly journals The influence of water resources on transformation of spatial-functional structure of the territory of the municipality of Mali Zvornik and the possibilities for the construction of new hydro power plants

2010 ◽  
Vol 90 (3) ◽  
pp. 189-206 ◽  
Author(s):  
Mila Pavlovic ◽  
Rajko Golic ◽  
Dejan Sabic
Keyword(s):  
Water Resources ◽  
Power Plants ◽  
Hydraulic Engineering ◽  
Functional Structure ◽  
Hydropower Plant ◽  
Small Scale ◽  
Hydro Power ◽  
Hydropower Plants ◽  
Economic Revitalization ◽  
Hydro Power Plants

The territory of the municipality of Mali Zvornik is, from the aspect of morphology and spatial-functional structure, a heterogeneous area. It is located in the valley of the Drina River and in hilly-mountainous part of Podrinjske mountains. The area of the municipality is 184 km?, with 14076 inhabitants (2002). The importance of water resources for the development of the municipality, particularly of the hydropower plant (HPP) ?Zvornik?, is analyzed in this paper. Inadequate use of hydro-energetic potential, possibilities for construction of new hydropower plants and economic reasons for their construction are also emphasized. The priorities of the development of hydraulic engineering are defined in relation to morphological and hydrological conditions. They refer to increase of power of the HPP ?Zvornik? and construction of small-scale hydropower plants in hilly-mountainous part of municipality. Considering depopulation processes in the villages of Mali Zvornik, hydraulic engineering, together with agriculture, forestry, exploitation of mineral goods and tourism, can be one of the factors of demographic and economic revitalization of this area.

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