Optimization of Kaplan Hydroturbine at Very Low Head With Rim-Driven Generator

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Ahmad I. Abbas ◽  
Ryoichi S. Amano ◽  
Mandana S. Saravani ◽  
Mohammad D. Qandil ◽  
Tomoki Sakamoto
Keyword(s):  
Power Output ◽  
Rotational Speed ◽  
Maximum Output Power ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Maximum Output ◽  
Cfd Analysis ◽  
Original Design ◽  
Speed Range ◽  
Low Head

The objective of the paper is to study the design and optimization of Kaplan hydroturbines for a very low head (less than 3 m), with a particular emphasis on the use of rim-drive electrical generators. The work is based on an experimental setup and computational fluid dynamics (CFD) analysis of various design parameters for maximum output power and efficiency. Two designs are presented in this paper. One is a 90-cm (35-in.) diameter vertical-oriented Kaplan hydroturbine system as an intended product capable of generating over 50 kW. The other is a smaller, 7.6-cm (3-in.) diameter horizontal-oriented system for prototyping and laboratory verification. Both are analyzed through CFD based on large eddy simulation (LES) of transient turbulence. Specific design for the runner and the stator, intake tube shape, as well as guide vanes upstream of the turbine was studied to get the most from the available head. The intent is to use 3D-printing manufacturing techniques, which may offer original design opportunities as well as the possibility of turbine and water conduit design customization as a function of the head and flow available from a specific site. Based on the CFD analysis, the 7.6-cm diameter system achieved the highest power output and the maximum efficiency at the rotational speed range of 1500–2000 rpm, while for the experimental testing, the optimum rotational speed range was 1000–1500 rpm. Because of the mismatch between CFD and experimental results, the CFD results were correlated due to the presence of air and friction; moreover, error and uncertainty analysis were presented for both methods. For the 90-cm case, the optimum performance was found at a rotational speed around 350 rpm according to the CFD results. Finally, investigating the shape of the intake tube of the hydroturbine setup can significantly increase the power output and the efficiency of the system.

Optimization of Kaplan Hydro-Turbine at Very Low Head With Rim-Driven Generator

2017 ◽  
Author(s):  
Ahmad I. Abbas ◽  
Tomoki Sakamoto ◽  
Mandana S. Saravani ◽  
Ryoichi S. Amano ◽  
Joseph Millevolte ◽  
...  
Keyword(s):  
Maximum Output Power ◽  
Design Parameters ◽  
Maximum Output ◽  
Original Design ◽  
Design And Optimization ◽  
Hydro Turbine ◽  
Eddy Simulation ◽  
Low Head ◽  
Manufacturing Techniques ◽  
Design Customization

The objective of the paper is to study the design and optimization of Kaplan hydro turbines for very low head (less than 3 meters), with a particular emphasis on the use of rim-drive electrical generators. The work is based on Computation Fluid Dynamics (CFD) analysis of a variety of design parameters for maximum output power and efficiency. Two designs are presented in the paper. One is a 90-cm (35-inch) diameter vertical-oriented Kaplan hydro turbine systems as an intended product capable of generating over 50 kW. The other is a smaller, 7.6-cm (3-inch) diameter horizontal-oriented system for prototyping and laboratory verification. Both are analyzed through CFD based on Large Eddy Simulation (LES) of transient turbulence. Certain design for the runner and the stator as well as guide vanes upstream of the turbine were studied to get the most from the available head. The intent is to use 3D-printing manufacturing techniques, which may offer original design opportunities as well as the possibility of turbine and water conduit design customization as a function of the head and flow available from a specific site.

Modeling and Simulation of MPPT-SEPIC Combined Bidirectional Control Inverse KY Converter Using ANFIS in Microgrid System

2016 ◽  
Vol 1 (2) ◽  
pp. 264 ◽  
Author(s):  
Soedibyo Soedibyo ◽  
Farid Dwi Murdianto ◽  
Suyanto Suyanto ◽  
Mochamad Ashari ◽  
Ontoseno Penangsang
Keyword(s):  
Energy Storage ◽  
Output Power ◽  
Distribution System ◽  
Maximum Output Power ◽  
Optimization Method ◽  
Photovoltaic System ◽  
Maximum Efficiency ◽  
Maximum Output ◽  
Pv System ◽  
Excess Power

<em>Photovoltaic system (PV) is widely used in various renewable energy application. The main problem of PV system is how to get the maximum output power which is integrated in microgrid system. Furthermore, the redundancy output power generated by on a distribution system should also be considered. This study utilizes the excess power for energy storage using bidirectional of KY inverse</em> <em>converter. Since the DC voltage which generated by PV and the energy storage will be converted into AC voltage using inverter toward load. This paper proposes ANFIS as search optimization method using SEPIC converter with a maximum efficiency of 99.95%</em> to impact to power generation performance  in microgrid system.

Revisit of Thermoelectric Efficiency and Figure-of-Merit

2014 ◽  
Vol 787 ◽  
pp. 195-197
Author(s):  
Chun Lei Wang ◽  
Yuan Hu Zhu ◽  
Wen Bin Su ◽  
Jian Liu ◽  
Ji Chao Li
Keyword(s):  
Power Generation ◽  
Power Factor ◽  
Power Output ◽  
Figure Of Merit ◽  
Maximum Output Power ◽  
Load Resistance ◽  
Maximum Output ◽  
Thermoelectric Efficiency ◽  
Physical Boundary ◽  
Thermoelectric Parameters

Thermoelectric efficiency power generation represented based on the transportation equations obtained under different physical boundary conditions in the present investigation. The figure-of-merit and power factor derived from optimizing thermoelectric efficiency and maximizing power output. It is interesting to note that the maximum output power reached when the load resistance was the thermoelectric adiabatic resistance, while the optimized thermoelectric efficiency responded the isothermal resistance. The possible approach to characterizing these thermoelectric parameters proposed in the present investigation.

scholarly journals Extended Bandwidth and Increased Efficiency Quasi-Doherty Power Amplifier Design With A Revised Approach For Load Modulation

2021 ◽  
Author(s):  
Seyedehmarzieh Rouhani ◽  
Kasra Rouhi ◽  
Adib Abrishamifar ◽  
Majid Tayarani
Keyword(s):  
Power Amplifier ◽  
High Power ◽  
Maximum Output Power ◽  
Input Power ◽  
Maximum Efficiency ◽  
Maximum Output ◽  
Power Added Efficiency ◽  
Active Feedback ◽  
Doherty Power Amplifier ◽  
Load Modulation

This paper presents an approach to power added efficiency (PAE) increase for Quasi-Doherty power amplifier (Q-DPA) design. For this aim, active feedback is utilized instead of a passive quarter wavelength transmission line (TL) usage, which is conventionally used in the DPA schematic. PAE increase can be done by applying an accurate load modulation to the main amplifier (PAmain), especially for technologies in which output impedance of the main power amplifier (Zout,main) considerably varies in both low and high power regions. Because such precise modulation is still based on a modified TL, this approach suffers from the inherent narrowband behavior of that TL. As a consequence, expecting a wideband DPA may not be satisfied in all cases. To deal with this issue, active feedback is used to play a role in reaching PAmain, which is not saturated before, to its maximum efficiency at the highest level of received input power (Pin) in the high power region. Following Zout,main trajectories in power and frequency sweeps simultaneously just by a passive TL are not needed anymore. Still, for the sake of preventing total PAE degradation due to the consummated power by the feedback path’s power amplifier (PAfeedback) should be limited, analytical confinement is provided in this work. A comparison is made between GaAs pHEMT 0.25um MMIC technology-based conventional DPA and the proposed revised approach based-DPA to verify the mentioned approach. The proposed PA shows maximum output power of 33.4 dBm, maximum PAE of 41.6, fractional bandwidth of 11%. The Q-DPA works with a maximum power gain of 24.16.

Efficiency and Optimal Loading of Contra-Rotating Marine Turbines

2011 ◽  
Author(s):  
Wei Xu ◽  
Spyros A. Kinnas
Keyword(s):  
Output Power ◽  
Maximum Output Power ◽  
Optimization Method ◽  
The Self ◽  
Maximum Efficiency ◽  
Maximum Output ◽  
Optimum Ratio ◽  
Line Model ◽  
Performance Effects ◽  
Lifting Line

In this paper, an optimization method is developed for determining the loading on each component, which leads to the maximum efficiency (i.e. maximum output power) of a contra-rotating turbine when subject to uniform inflow. The lifting line model is adopted and both the self-induced velocities and the interaction induced velocities between the front and the back components are included. The optimum ratio of rotational velocities for reducing the torque on support structures and the performance effects of the gap distance between two components are investigated. The optimum distance for two in-line turbines in a turbine farm is also analyzed.

scholarly journals Numerical optimization of the piezoelectric generators

2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060016
Author(s):  
V. A. Chebanenko ◽  
I. V. Zhilyaev ◽  
A. N. Soloviev ◽  
A. V. Cherpakov ◽  
I. A. Parinov
Keyword(s):  
Finite Element Method ◽  
Numerical Optimization ◽  
Output Voltage ◽  
Optimization Problem ◽  
Optimization Technique ◽  
Maximum Output Power ◽  
Operating Conditions ◽  
Design Parameters ◽  
Maximum Output ◽  
The Finite Element Method

This paper presents the application of the Pareto-based multicriteria optimization technique to problems of increasing the efficiency of piezoelectric generators (PEGs). The optimization problem was solved for two types of generators: cantilever and stack. For the cantilever generator, the task was to optimize the design in such a way as to obtain the maximum output power for a given mechanical excitation. The optimization process was divided into several stages, which significantly reduced the amount of calculations. The task of optimizing the stack type for a given form of mechanical loading consisted in finding the geometric parameters of the generator at which the output voltage and power would be maximum. In the result of solving both problems, sets of geometric design parameters of PEGs were obtained, on the basis of which efficient transducers can be developed for specific operating conditions. It turned out that this technique is more suitable for optimizing the design of cantilever generators than for stack ones in given constraints. The solution of both problems was realized using the finite element method.

The Effect of Design Parameters on the Performance of Flagellar Propeller at Low Reynolds Number

2011 ◽  
Author(s):  
Hyejin Jeon ◽  
Yoon-Cheol Kim ◽  
Eun Goh ◽  
Dongwook Yim ◽  
Songwan Jin ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Rotational Speed ◽  
Low Reynolds Number ◽  
Stereoscopic Particle Image Velocimetry ◽  
Macroscopic Model ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Working Fluid ◽  
Inertia Force ◽  
Low Reynolds

To drive a small object which swims in low Reynolds number situation, we need a new type of propeller which is optimized for low Reynolds number usage since the flow at low Reynolds numbers is dominated by viscous force instead of inertia force. Propeller in a shape of bacterial flagellum can be a strong candidate for propeller of small swimming object. In this paper, we visualized velocity field induced by flagellar shaped propeller using stereoscopic particle image velocimetry. We also have experimentally evaluated the effect of pitch and rotational speeds on the performance of flagellar shaped propeller inspired by flagellum of E.coli using macroscopic model. Silicone oil whose viscosity is 100 times larger than water is used as working fluid to make low Reynolds number situation using macroscopic model. Thrust, torque and velocity were measured as a function of pitch and rotational speed, and efficiency was calculated using measured results. We found that the maximum efficiency of flagellar propeller reaches where the pitch angle is about 40°. However, the effect of rotational speed on the efficiency is relatively smaller than that of pitch. And the flow pattern behind the rotating propeller was altered by pitch of the propeller.

scholarly journals Research on the Power Output Characteristics of a Coupling Transformer in D-FACTS

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4709
Author(s):  
Zhimin He ◽  
Shuo Zhang ◽  
Yadong Liu ◽  
Fan Wu ◽  
Gehao Sheng ◽  
...  
Keyword(s):  
Output Power ◽  
Power Output ◽  
Network Flow ◽  
Characteristic Curve ◽  
Maximum Output Power ◽  
Current Source ◽  
Maximum Power ◽  
Constant Current ◽  
Maximum Output ◽  
Line Current

The series coupling distributed flexible AC transmission system (D-FACTS) device couples the secondary side compensating reactance to the primary side based on the principle of transformer, thus realizing the goal of adjusting the transmission line parameters and controlling the distribution network flow. The coupling transformer is the most important power conversion part in the D-FACTS device but has different working principles of mutual inductor. The magnetizing current of the coupling transformer changes within a large range, which makes the traditional power output model of mutual inductor inapplicable. In this paper, the power output model of coupling transformer was constructed by viewing the coupling transformer as a constant current source. Moreover, the corresponding relationship between the output power of the transformer and related parameters, as well as between variations of reactive output power and active loss power with load changes, was analyzed. Some conclusions were drawn: (1) the output power characteristic curve of the coupling transformer was acquired; (2) given a constant line current, the maximum power was achieved when the system’s capacitive reactance and the internal resistance of the transformer matched, and the maximum power was unrelated to the number of turns of the coupling transformer; (3) the output power changed with the variation of the line current, and there was a proportional relationship between the maximum power and the square of the line current. Next, the relationship between the maximum output power and the air gap thickness of the magnetic core was discussed. Finally, these conclusions were proved accurate via experiments.

scholarly journals Effects of Design Parameters on Fuel Economy and Output Power in an Automotive Thermoelectric Generator

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3274 ◽  
Author(s):  
Martí Comamala ◽  
Ivan Ruiz Cózar ◽  
Albert Massaguer ◽  
Eduard Massaguer ◽  
Toni Pujol
Keyword(s):  
Fuel Consumption ◽  
Output Power ◽  
Fuel Economy ◽  
Waste Heat ◽  
Maximum Output Power ◽  
Back Pressure ◽  
Design Parameters ◽  
Limiting Factor ◽  
Maximum Output ◽  
Sustainable Mobility

The need for more sustainable mobility promoted research into the use of waste heat to reduce emissions and fuel consumption. As such, thermoelectric generation is a promising technique thanks to its robustness and simplicity. Automotive thermoelectric generators (ATEGs) are installed in the tailpipe and convert heat directly into electricity. Previous works on ATEGs mainly focused on extracting the maximum amount of electrical power. However, the back pressure caused by the ATEG heavily influences fuel consumption. Here, an ATEG numerical model was first validated with experimental data and then applied to investigate the effects that modifying the main ATEG design parameters had on both fuel economy and output power. The cooling flow rate and the geometrical dimensions of the heat exchanger on the hot side and the cold side of the ATEG were varied. The design that produced the maximum output power differed from that which maximized fuel economy. Back pressure was the most limiting factor in attaining fuel savings. Back pressure values lower than 5 mbar led to a < 0.2% increase in fuel consumption. In the ATEG design analyzed here, the generation of electrical output power reduced fuel consumption by a maximum of 0.5%.

Development and experimental research on circumferential impulse microturbine power generation system

2013 ◽  
Vol 228 (2) ◽  
pp. 378-387 ◽  
Author(s):  
L Zhang ◽  
GZ Tang ◽  
ZB Liao ◽  
HC Shang
Keyword(s):  
Power Generation ◽  
Output Power ◽  
Rotational Speed ◽  
Maximum Output Power ◽  
Iron Core ◽  
Maximum Output ◽  
Generation System ◽  
Coil System ◽  
Coil Structure ◽  
Power Generation System

Circumferential impulse microturbine is a key component of the micro-electro-mechanical system and provides power to the latter. An innovative concept of microturbine power generation system was presented, and prototype improved circumferential impulse microturbine power generation systems were developed, and their output performances were tested. It is validated that the system can operate at a high speed in a dynamic equilibrium state using rolling bearings, and it is found that the output power and rotational speed of a six-blade turbine hollow-cup coil structure is higher than the output power and rotational speed of a six-blade turbine iron-core coil structure. The maximum output power of the eight-blade turbine hollow-cup coil power generation system is 1.1 W, and the maximum turbine rotational speed is 55,000 r/min. The maximum output power of the eight-blade turbine hollow-cup coil system increases up to 25% when compared to the six-blade turbine hollow-cup coil system and increases up to 83% when compared to the six-blade turbine iron-core coil system.

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