scholarly journals Novel Design of Speed-increasing Compound Coupled Hydromechanical Transmission on Tidal Current Turbine for Power Generation

2020 ◽  
Vol 162 ◽  
pp. 03001
Author(s):  
Xiaohan Dong ◽  
Zhao Wang ◽  
Pengfei Shen ◽  
Yurun Song ◽  
Jin Yu

A key topic discussed in the energy industry has long been how to steadily convert tidal energy into mechanical energy and then electrical power. Gear transmissions are widely used in mechanical systems for electrical power production, converting low-speed input rotation into high-speed output rotation to drive a generator rotor. However, to achieve a large speed ratio and stepless speed change, gear transmissions must be accompanied by complex structures and high-precision manufacturing technology. The application of gear transmissions in tidal energy power generation must therefore come at a high cost. A large speed ratio and stepless speed-changing capability are precisely the two essential elements of the mechanical system for tidal energy power generation. In this paper, a new type of speed-increasing CCHMT has been proposed that is capable of achieving large transmission ratio speed change between the blade rotor input and the generator rotor output. It is also capable of changing the input speed steplessly into a stable output speed suitable for power generation and for high-quality electric power production. To verify the feasibility of using a speed-increasing CCHMT in tidal energy, a simulation model has been established for the wave power at the input end. With the assistance of a volumetric speed-control system and hydraulic accumulator, the speed-increasing CCHMT can stably transmit disordered input speed. Simulation results show that the output rotational speed gained a stable amplification ratio within 20 and 30. The mean square error of the rotational speed was controlled to within 29 and the output speed is limited within 85% to 115% of the average output speed, thus ensuring the quality of power generation.

Author(s):  
Hwabhin Kwon ◽  
Heesung Park

Abstract A turboexpander for the propane de-hydrogenation process with blade and splitter has been numerically investigated. Since the turboexpander expands fluid from higher inlet pressure to lower discharge pressure, the kinetic energy of fluid is converted into useful mechanical energy. The efficiency and power generation with the designed turboexpander have been simulated with different operating conditions. The pressure ratio between inlet and outlet and rotational speed are varied to characterize the performance of the turboexpander as an electrical power generator. The numerical simulations have shown the vortex at the trailing edges of blade and splitter which decreases the efficiency. The rotational speed and the pressure ratio are parameterized to obtain operation conditions which achieve high power generation and efficiency. Consequently, the generated power from 614.12 kW to 693.45kW is obtained at the normal rotational speed and the pressure ratio between 1.75 to 2.22.


2018 ◽  
Author(s):  
Michael Ozeh ◽  
Ashreet Mishra ◽  
Xiuling Wang

The Archimedes wind turbine boasts an innovative blade design with the potential of harvesting energy from wind with much more efficiency. The blade design utilizes both lift and drag forces, and boasts several other advantages over conventional horizontal axis and vertical axis wind turbines, which implies higher power production efficiency and a possibility of being used in urban areas with attendant low wind speed regimes for small scale power generation, being more portable. However, there exists a dearth of experimental reports on the Archimedes wind turbine besides CFD simulations, to observe and study its real-life performance and power production potential. This paper is an experimental report on the design and wind test of the Archimedes wind turbine prototype, together with calculations made to gauge its tip speed ratio, power output and energy production potential. To show the viability of the prototype, the power produced is used to charge a HTC Desire cell phone, which proves that it can be relied upon to meet the title objective of small scale power storage with a power bank. Results are thereafter compared to other published work and show relatively good agreement. Minor deviations are attributed to the challenges encountered during the fabrication process.


2019 ◽  
Vol 4 (2) ◽  
pp. 7-11 ◽  
Author(s):  
Timothy Oluwaseun Araoye ◽  
C. A. Mgbachi ◽  
Olushola Adebiyi Omosebi ◽  
Oluwaseun Damilola Ajayi ◽  
Adeleye Qasim Olaniyan

Biogas power generation is renewable energy made from biological materials. Biogas power production is technology which helps in development of sustainable energy supply systems. This paper develops Genetic Algorithm optimization model for Biogas electrical power generation of Ilora in Oyo, Oyo state. The production is done using co-digestion system of pig dung and Poultry dung under the process of anaerobic digestion. The pig dung and poultry dung were mixed 50:50%. MATLAB and VISUAL BASIC Software was used to carry out simulations to develop optimized Genetic Algorithm model for Biogas power production with aims to improving electricity accessibility and durability of the community. The results of the research reveal the Empirical Biogas power production without and with Genetic Algorithm optimization. The Result showed that biogas electrical power generated without and with Genetic Algorithm Optimization were 5KW and 11.18KW respectively. The biogas power generation was increased by 6.18KW, which is 38.2% increase after Genetic Algorithm optimization. The results show the application of the Genetic Algorithm optimization model which can be used to improving Biogas power generation when amount of methane gas produced from the animal dung varies with speed of thermal rotating shaft.


Author(s):  
Jahangir Rastegar ◽  
Richard Murray

This is a review of two patents relating to electrical power generation on-board gun-fired munitions. The devices harvest mechanical energy from the motion of the projectile (e.g. the axial firing acceleration), and then convert the energy from mechanical to electrical using novel mechanisms and materials such as piezoelectric elements. The devices are particularly important for several reasons. Firstly, the devices are inherently safe because the root source of the electrical energy is the motion of the projectile; therefore no electrical energy can be produced until after the projectile is fired. Second, the devices have a much longer shelf-life than competing electrical power sources such as batteries. Finally, the devices are simple, rugged, and reliable making them ideal for the harsh environment on-board gun-fired projectiles. In addition to presenting the general approach, the logical framework of the patented embodiments is presented, especially with respect to the types of motion used for harvesting and the challenges presented by the varied magnitudes of those motions in different weapon platforms.


Author(s):  
Raunak Raj

Abstract: In the present situation power becomes basic need for human life. Energy is responsible for major developments of any country’s economy. Conventional energy sources generate most of the energy of today’s world. But the population is increasing day by day and the conventional energy sources are diminishing. Moreover, these conventional energy sources are polluting and responsible for global warming. So, nonconventional sources are needed to be developed for power generation which are clean, environment friendly and sustainable. In this research we propose a renewable non-conventional energy source based on speed breaker mechanism. Our project is to enlighten the streets utilizing the jerking pressure which is wasted during the vehicles passes over speed breaker in roadside. We can tap the energy generated by moving vehicles and produce power by using the speed breaker as power generating unit. The kinetic energy of the moving vehicles can be converted into mechanical energy through rack and pinion mechanism and this mechanical energy will be converted to electrical energy using generator which will be used for lighting the street lights. Therefore, by using this mechanism we can save lot of energy which can fulfill our future demands. Keywords: kinetic energy, speed breaker, rack & pinion, generator, non-conventional energy, street light.


Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 177
Author(s):  
Suzana Uran ◽  
Matjaž Malok ◽  
Božidar Bratina ◽  
Riko Šafarič

Constructing a micro-sized microfluidic motor always involves the problem of how to transfer the mechanical energy out of the motor. The paper presents several experiments with pot-like microfluidic rotational motor structures driven by two perpendicular sine and cosine vibrations with amplitudes around 10 μm in the frequency region from 200 Hz to 500 Hz. The extensive theoretical research based on the mathematical model of the liquid streaming in a pot-like structure was the base for the successful real-life laboratory application of a microfluidic rotational motor. The final microfluidic motor structure allowed transferring the rotational mechanical energy out of the motor with a central axis. The main practical challenge of the research was to find the proper balance between the torque, due to friction in the bearings and the motor’s maximal torque. The presented motor, with sizes 1 mm by 0.6 mm, reached the maximal rotational speed in both directions between −15 rad/s to +14 rad/s, with the estimated maximal torque of 0.1 pNm. The measured frequency characteristics of vibration amplitudes and phase angle between the directions of both vibrational amplitudes and rotational speed of the motor rotor against frequency of vibrations, allowed us to understand how to build the pot-like microfluidic rotational motor.


2017 ◽  
Vol 24 (1) ◽  
pp. 152-167
Author(s):  
Izhak Bucher ◽  
Ran Gabai ◽  
Harel Plat ◽  
Amit Dolev ◽  
Eyal Setter

Vibrations are often represented as a sum of standing waves in space, i.e. normal modes of vibration. While this can be mathematically accurate, the representation as travelling waves can be compact and more appropriate from a physical point of view, in particular when the energy flux along the structure is meaningful. The quantification of travelling waves assists in computing the energy being transferred and propagated along a structure. It can provide local as well as global information about the structure through which the mechanical energy flows. Presented in this paper is a new method to quantify the fraction of mechanical power being transmitted in a vibration cycle at a specific direction in space using measured data. It is shown that the method can detect local defects causing slight non-uniformity of the energy flux. Equivalence is being made with the electrical power factor and electromagnetic standing waves ratio, commonly employed in such cases. Other methods to perform experiment based wave identification in one-dimension are compared with the power flow based identification. Including a signal processing approach that fits an ellipse to the complex amplitude curve and Hilbert transform for obtaining the local phase and amplitude. A new representation of the active and reactive power flow is developed and its relationship to standing waves ratio is demonstrated analytically and experimentally.


Author(s):  
J. A. Chattha ◽  
M. S. Khan ◽  
H. Iftekhar ◽  
S. Shahid

Pakistan has a hydro potential of approximately 42,000MW; however only 7,000MW is being utilized for electrical power production [1, 2]. Out of 42,000 MW, micro hydro potential is about 1,300MW [1, 2]. For typical site conditions (available flow rate and head) in Pakistan, Cross Flow Turbines (CFTs) are best suited for medium head 5–150m [3] for micro-hydro power production. The design of CFT generally includes details of; the diameter of the CFT runner, number of blades, radius of curvature and diameter ratio. This paper discusses the design of various CFTs for typical Pakistan site conditions in order to standardize the design of CFTs based on efficiency that is best suited for a given site conditions. The turbine efficiency as a function of specific speed will provide a guide for cross flow turbine selection based on standardized turbine for manufacturing purposes. Standardization of CFT design will not only facilitate manufacturing of CFT based on the available site conditions with high turbine efficiency but also result in reduced manufacturing cost.


Sign in / Sign up

Export Citation Format

Share Document