Small Scale Hydro-electric Energy

1990 ◽  
Keyword(s):  
Electric Energy ◽  
Small Scale

scholarly journals Comparison of Two Single Stage Low-Pressure Rotary Lobe Expander Geometries in Terms of Operation

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4512
Author(s):  
Michalina Kurkus-Gruszecka ◽  
Piotr Krawczyk
Keyword(s):  
Cfd Simulation ◽  
Mechanical Energy ◽  
Electric Energy ◽  
Low Pressure ◽  
Single Stage ◽  
Small Scale ◽  
Operational Parameters ◽  
Data Simulation ◽  
Time Step ◽  
Geometry Model

In the article the computational fluid dynamics (CFD) simulation and calculated operational parameters of the single stage low-pressure rotary lobe expander compared with the values obtained from a different geometry simulation are presented. Low-pressure rotary lobe expanders are rotary engines that use a compressed gas to produce mechanical energy, which in turn can be converted into another form, i.e., electric energy. Currently, expanders are used in narrow areas, but have a large potential in the energy production from gases of low thermodynamic parameters. The first geometry model was designed on the basis of an industrial device and validated with the empirical data. Simulation of the second geometry was made based on a validated model in order to estimate the operational parameters of the device. The CFD model included the transient simulation of compressible fluid in the geometry changing over time and the rotors motion around two rotation axes. The numerical model was implemented in ANSYS CFX software. After obtaining simulation results in the form of parameters monitors for each time step, a number of calculations were performed using a written code analysing the CFD program output files. The article presents the calculation results and the geometries comparison in terms of work efficiency. The research indicated that the construction of the device on a small scale could cause a significant decrease in the aforementioned parameter, caused by medium leaks in the expander clearances.

scholarly journals Numerical Investigation of Pipelines Modeling in Small-Scale Concentrated Solar Combined Heat and Power Plants

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 429 ◽  
Author(s):  
Roberto Tascioni ◽  
Luca Cioccolanti ◽  
Luca Del Zotto ◽  
Emanuele Habib
Keyword(s):  
Flow Rate ◽  
Power Plants ◽  
Winter Season ◽  
Electric Energy ◽  
Combined Heat And Power ◽  
Heat Transfer Fluid ◽  
Energy Output ◽  
Small Scale ◽  
Longitudinal Model ◽  
Lumped Model

In this paper four different detailed models of pipelines are proposed and compared to assess the thermal losses in small-scale concentrated solar combined heat and power plants. Indeed, previous numerical analyses carried out by some of the authors have revealed the high impact of pipelines on the performance of these plants because of their thermal inertia. Hence, in this work the proposed models are firstly compared to each other for varying temperature increase and mass flow rate. Such comparison shows that the one-dimensional (1D) longitudinal model is in good agreement with the results of the more detailed two-dimensional (2D) model at any temperature gradient for heat transfer fluid velocities higher than 0.1 m/s whilst the lumped model agrees only at velocities higher than 1 m/s. Then, the 1D longitudinal model is implemented in a quasi-steady-state Simulink model of an innovative microscale concentrated solar combined heat and power plant and its performances evaluated. Compared to the results obtained using the Simscape library model of the tube, the performances of the plant show appreciable discrepancies during the winter season. Indeed, whenever the longitudinal thermal gradient of the fluid inside the pipeline is high (as at part-load conditions in winter season), the lumped model becomes inaccurate with more than 20% of deviation of the thermal losses and 30% of the organic Rankine cycle (ORC) electric energy output with respect to the 1D longitudinal model. Therefore, the analysis proves that an hybrid model able to switch from a 1D longitudinal model to a zero-dimensional (0D) model with delay based on the fluid flow rate is recommended to obtain results accurate enough whilst limiting the computational efforts.

scholarly journals Parametric Optimisation of a Trigenerative Small Scale Compressed Air Energy Storage System

Proceedings ◽  
2019 ◽  
Vol 23 (1) ◽  
pp. 5
Author(s):  
Mohamad Cheayb ◽  
Sébastien Poncet ◽  
Mylène Marin-Gallego ◽  
Mohand Tazerout
Keyword(s):  
Energy Storage ◽  
Storage System ◽  
Electric Energy ◽  
Optimal Solution ◽  
Energy Storage System ◽  
Compressed Air ◽  
Design Parameters ◽  
Small Scale ◽  
Compressed Air Energy Storage ◽  
Study Results

Recently, major improvement on compressed air energy storage technology has been made by using the heat of compression for heating energy or using it to preheat the compressed air in the expansion phase and by demonstrating its ability to produce cooling energy. Thus, the trigenerative compressed air energy storage has been introduced. In this paper, we introduce a configuration of trigenerative compressed air energy storage system giving the preference to the electric energy production. The study then focuses on undertaking an optimization study via a parametric analysis considering the mutual effects of parameters. This analysis is applied to a micro-scale application including the existing technological aspects. The parametric study results applied on the hot temperature of the thermal energy storage indicate the possibility to find an optimal solution as a trade-off between system performances and other parameters reflecting its cost. On the contrary, the selection of the maximal storage pressure cannot be achieved by finding a compromise between energy density and system efficiency. A complete study of other design parameters will be addressed in a future publication.

scholarly journals Harvest of Motion

2008 ◽  
Vol 130 (09) ◽  
pp. 56-58 ◽  
Author(s):  
Brian S. Hendrickson ◽  
Stuart B. Brown
Keyword(s):  
Energy Harvesting ◽  
Water Waves ◽  
Electric Energy ◽  
Low Frequency ◽  
Rechargeable Batteries ◽  
Small Scale ◽  
Catch And Release ◽  
Limited Life ◽  
Initial Research

This article discusses that a small-scale generator uses a catch-and-release strategy that can turn a casual stroll into useful electric energy. Many devices now require fractions of a watt continuously, often with occasional bursts of 1 to 10 W during peak activity. However, batteries occupy device volume and have limited life. Even rechargeable batteries can withstand only a finite number of charge cycles and, perhaps most important, recharging them can be inconvenient or expensive. Engineers must develop strategies to harness the abundant energy in low-frequency, time-varying motion before energy harvesting can achieve its greatest potential. Water waves, swaying and bouncing structures, and biomechanics are potential environmental energy sources that are largely out of the reach of the current vibration-inspired, motion harvesting technologies. Being able to economically convert low-speed motion to electricity will be a key to realizing practical long-term power generation for distributed devices. The Veryst energy-harvesting concept is one approach that intends to do just that. As with other energy harvesting projects, much work remains, but initial research and development suggest strong potential.

scholarly journals Functioning of the fuel-energy complex of Lviv Oblast in modern conditions

2019 ◽  
Vol 28 (4) ◽  
pp. 717-726
Author(s):  
Irina V. Poruchynska ◽  
Volodymyr I. Poruchynsky ◽  
Andrey N. Slashchuk ◽  
Alla G. Potapova
Keyword(s):  
Alternative Energy ◽  
Electric Energy ◽  
General Characteristic ◽  
Primary Energy ◽  
Technical Condition ◽  
Energy Resources ◽  
Small Scale ◽  
Energy Complex ◽  
Power Stations ◽  
Low Efficiency

The article provides a general characteristic and detailed analysis of the main spheres of the fuel and energy complex of Lviv Oblast. The paper proves the importance of development of the fuel and energy complex for the economy of Lviv Oblast and the welfare of its residents, for it fulfills the needs of the entire economic complex in fuel and energy, creates preconditions for development of various types of production, forms the basis for improvement of energy security of the region and country in general. The peculiarities of development of the fuel and energy complex were determined, the main of which are: large amount of coal extracted by mining, small-scale extraction of peat, absence of major electric power stations and high percentage of incoming electric energy from other regions. The paper gives a characterization of the energy balance in the Oblast, and also structure of reserves of coal mines and oil deposits. Areas promising for extraction of bituminous and brown coal, oil, gas, peat and other fuel resources were determined. The structure of consumption of fuel-energy resources by types of organic fuel was determined. Patterns of consumption of the main types of energy carriers in the region were distinguished. The structure of capacities of alternative energy resources in Lviv Oblast was determined. We determined the reasons for the low efficiency of use of natural resources and peculiarities and problems of the development of the energy sphere in the region, the main of which are the unsatisfactory technical condition of the objects of the fuel and energy complex, non-effective system of management in the sphere, absence of new sources of providing primary energy resources. We suggested recommendations on increasing the efficiency of functioning of the fuel and energy complex on the basis of use of non-traditional types of energy sources, i.e.: energy of sun, wind, biomass of solid fuel and others, which would allow natural and financial resources to be saved.

scholarly journals Numerical Study on the Efficiency of Biomass and Municipal Waste Fixed-Bed Co-Gasification

2019 ◽  
Vol 114 ◽  
pp. 06006 ◽  
Author(s):  
Igor G. Donskoy
Keyword(s):  
Sewage Sludge ◽  
Energy Production ◽  
Numerical Study ◽  
Fixed Bed ◽  
Electric Energy ◽  
Process Efficiency ◽  
Small Scale ◽  
Process Conditions ◽  
Stoichiometric Ratio ◽  
Process Characteristics

The utilization of combustible waste, such as sewage sludge, can be combined with energy production for small-scale consumers. One of the ways of such utilization can be gasification, which makes it possible to obtain a combustible gas suitable for thermal and electric energy production. The aim of this study is to estimate the efficiency of sewage sludge co-conversion with woody biomass using mathematical model that allows to investigate process characteristics under different process conditions (air stoichiometric ratio, fuel mixture composition, initial moisture of sewage sludge). Dependencies of gasification process characteristics are evaluated and compared with published experimental data. Fixed-bed downdraft process is investigated related to using of wood and sewage sludge mixtures. New results are obtained considering process efficiency dependence on input fuel composition, method is proposed to estimate acceptable fuel mixtures based on agglomeration and efficiency requirements.

scholarly journals The implementation of small-scale hydropower stations in slow flow micro-rivers: a case study of Uzbekistan

2019 ◽  
Vol 135 ◽  
pp. 01036 ◽  
Author(s):  
Dilshod Kodirov ◽  
Obid Tursunov ◽  
Sevarakhon Parpieva ◽  
Nusratillo Toshpulatov ◽  
Kurash Kubyashev ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Fossil Fuels ◽  
Experimental Studies ◽  
Electric Energy ◽  
Point Of View ◽  
Small Scale ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Independent Basis ◽  
Hydropower Stations

Electric energy production in small-scale hydropower stations is attractive from both an ecological and an economical point of view. Technological innovations and measures to lessen environmental impacts make small-scale hydropower stations inexpensive and justified energy sources that provide renewable energy on an independent basis and help not only to protect the environment but also to weaken human dependence on fossil fuels. This study is devoted to finding solutions based on renewable energy technologies and innovations in Uzbekistan. This article is devoted to the development of a water wheel experimental model for the micro-hydroelectric power station. Experimental studies were carried out on the basis of this model and obtained results were used in the preliminary calculations. The results from the calculations showed that the installation can generate 7-11 kWh of electricity per hour, about 168-264 kWh of electricity per day and 61 to 96 MWh of electricity per year.

scholarly journals Storage Gravitational Energy for Small Scale Industrial and Residential Applications

Inventions ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 64 ◽  
Author(s):  
Ana Cristina Ruoso ◽  
Nattan Roberto Caetano ◽  
Luiz Alberto Oliveira Rocha
Keyword(s):  
Energy Storage ◽  
Storage System ◽  
Short Interval ◽  
Photovoltaic Cells ◽  
Electric Energy ◽  
Gravitational Energy ◽  
Gravitational Potential Energy ◽  
Small Scale ◽  
Stable Form ◽  
High Demand

Photovoltaic cells produce electric energy in a short interval during a period of low demand and show high levels of intermittency. One of the well-known solutions is to store the energy and convert it into a more stable form, to transform again into electricity during periods of high demand, in which the energy has a higher value. This process provides economic viability for most energy-storage projects, even for the least efficient and most common, such as batteries. Therefore, this paper aims to propose a storage system that operates with gravitational potential energy, considering a small-scale use. The development of this methodology presents the mathematical modeling of the system and compares the main characteristics with other systems. The dimensions of the considered system are 12-m shaft, 5-m piston height, and 4 m of diameter; it presented an energy storage of 11 kWh. Also, it has an efficiency of about 90%, a lifetime of 50 years, and higher storage densities compared to other systems.

scholarly journals Analysis of Performance and Control of DC Microgrids as Electricity Providers for Renewable Energy

2021 ◽  
Vol 317 ◽  
pp. 04032
Author(s):  
Denis ◽  
Enda Wista Sinuraya ◽  
Jaka Windarta ◽  
Yosua Alvin Adi Soetrisno ◽  
Kurnianto Fernanda
Keyword(s):  
Distributed Generation ◽  
Fossil Fuels ◽  
Service Providers ◽  
Electric Energy ◽  
Electrical Energy ◽  
System Stability ◽  
Small Scale ◽  
Distributed Generators ◽  
Drastic Increase ◽  
And Control

The increase in demand for electrical energy is increasing rapidly, in line with economic growth. In developing the electricity system, electrical energy service providers must provide electrical energy according to demand with good quality. The generation of conventional electric energy systems that use fossil fuels faces depleting fossil fuel sources, poor efficiency, and environmental pollution. This technology is known as Distributed Generation (DG). Distributed Generation (DG) or Micro Grid (MG) is a small-scale power plant located close to the load. The use of distributed generators can improve the entire system's efficiency, reduce transmission losses, reduce pollution, and ensure the continuity of the distribution of electrical energy. However, the drastic increase in the use of DG causes problems in the form of voltage and frequency stability which will be disturbed due to rapid changes in the generation and loading rates. If this is left unchecked, it can harm system security and reliability. A proper control strategy will restore system stability in the event of an imbalance.

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