Application for New Mechanicals Stored Energy Systems
APPLICATIONFOR NEW MECHANICALS STORED ENERGY SYSTEMS
Flywheelshave been applied for over 5,000 years in the potters` and thetextile spindles. They were then adapted to the use in machines inthe course of the industrial revolution. The idea behind the firstflywheels is that the objects in motion continue to be in motionunless they are subjected to an outside force. Typically, theflywheel systems have the potential to store kinetic energy that isthe energy of mass in movement by constant spinning of a dense rotorin an area with little friction. The stored kinetic energy in theflywheel is normally about its mass, the square of its rotationalspeed (RPM), and the square of its radius.
Theflywheel generators can be widely applied in the provision of powerthat can be used for various functions since this power can be usedto run anything. This is a promising field since the initial energyis tapped from the solar panel that makes it produce green energy. Itimplies that very little damage is caused to the environment.Typically, it entails a pathway before the final usable energy isobtained. Obtaining energy using this method is crucial inmaintaining the safety of the environment since it is a more naturalprocess. This essay aims at discussing the major steps involved inthe production of this power and it also states some of theadvantages and disadvantages of using this method (Dincer, et al.2013).
Theoreticalsurvey of the system
Thedevelopment of an optimal flywheel for a particular application needssensibly balancing various factors. For instance, an increase in therotational speed of the flywheel will, in turn, increase he storedenergy. On the other hand, it`s also crucial to note that it isassociated with an increase in the stress on the flywheel, thus, itrequires the use of a more expensive and stronger material in theplace of the rotor. On that, a larger or a heavier diameter fly wheelwill also increase the storage of energy (Acha, 2002).
Typically,this flywheel technology incorporates a motor, generator, and aflywheel energy source to a well-designed and finance clarification.The flywheel rotor rotates at a continual speed so that it can storekinetic energy as a mechanism for the storage of the energy. It isalso substantial to note that in case the utility power is lost,there is the need for a short-term backup of power, and thus, theflywheel partially becomes the generator. This results in theconversion of the kinetic energy to electricity, and thus it isfunctional. The initial power obtained by the motor is typicallyobtained from the solar panel that convert sunlight to electricenergy that is crucial in the functioning of the flywheel.
Theflywheel largely constitutes of three majors parts in its internalstructure that work in unison to provide the final energy that isused for various purposes. To begin with the magnetic unloadingtechnology partially supports the flywheel rotor. Its purpose is tounload most of the weight of the flywheel from the field-replaceablemechanical bearing container. Secondly, it is also built with asingle-piece forged steel rotor that revolves at 7,700 revolutionsper minute and it is also known to store about 12.65 MJ of energy.Also, the tip of this rotor moves at about 584 MPH. Its structurealso consists of a rough vacuum that is responsible for evacuatingthe chamber thus reducing the drag on the rotor to step up itsefficiency and also to extend the life of the system (Laughton, etal. 2003). The motor is also crucial in the design and functioning ofthis system. Typically, an input of about 1 KW can keep the rotorrotating at about 7,700 revolutions per minute (Chastain, 2006).
Typically,the main idea is that the solar panel is the starter of the wholeprocess, and it converts sunlight to electric energy that is thenintegrated into the system. The electric motor gets the power fromthe solar panel, and it converts it to the kinetic energy that iscritical in the movement of the flywheel. The flywheel is in turnconnected to the generator, and it moves it so that it can generatepower in the form of electricity. This resultant power is applied inrunning the motor, and the extra power that is the final resultantpower can be used in any application in large scale. An analyst,Gray, came up with a model which he named Velkess and is animprovement of the traditional flywheel. He borrowed the idea of amechanical engineer called John Vance. Vance conducted an extensiveresearch on flywheels as a professor at Texas A&M University. Theoverview of his model does not use magnets but rather a rotatingwheel suspended in the gimbal. The gimbal is asymmetrical such thatthe two rotation axes present (flywheel and rotor axis), which compelthe inducting DC motor that is brushless, are not placed on the samesurface and vary in frequency periods (Atkinson, 2008). This makesthe resonance effects that harden the control of traditionalflywheels damp. Where the gimbal is concerned, there is thetranslation of resonance in one plane into the other, which at thesame frequency is non-resonant. The device is built by engineeringtolerances that are very loose, about one-sixteenth of an inch(Huebner, 2001). Gray minimized material cost by making his wheel outof "E-glass"-grade fiberglass that is cheap and veryflexible instead of carbon fiber or steel which is acquired veryexpensive.
Theflywheel is a primary source of renewable energy that has problemswith the storage of a lot of electric energy on a wide scale butcheaply. A new design for a flywheel by Bill Gray, a Silicon Valleyinventor, is set to produce a storage that is of high scale foraround 1,333 dollars for one kilowatt. This price is competitive withother storage facilities such as compressed air and pumped hydro. Itsefficiency is more than 80 percent making it able to rival otheralternatives that are considered the best. The guarantee is at tenyears. This model would complement an off-grid house that has a solarphotovoltaic (PV) installed system perfectly as it can fully chargewithin five hours. This is the same duration most solar PV systemstake to charge. It also stores 15 KW-hours of power that issufficient in running a modest house from the time the sun sets towhen it rises. The name given to Gray`s model is Velkess (Very LargeKinetic Energy Storage System).
Thismodel is an improvement to the traditional flywheel in the sensethat, it has a better management of the natural "wobble" ofa mass that spins. The expensive nature of traditional flywheels isas a result of the alignment of the natural axis of the rotation ofthe wheel with the rotation of the generator desired. For thatreason, there is a struggle to make the natural wobble minimal. Thisutilizes magnets and bearings that are very expensive, engineeringmaterials with very high precision (rigid steel or carbon fiber thatis of a high grade) making them very expensive (Grote, et al. 2009).
Graydid not attempt to fight the wobble. He only redirected it by hangingthe wheel freely within a gimbal. According to research by aBoston-based analyst, storage of energy could be less globally by2017 if only the prototype of Velkess can be established at theadvertised performance and price. This could be the solution to theperiodicity problem facing renewables at once. The Velkess issatisfactory of the essential factor for storing electricity(scaling) there can be multiple linkages of units in parallel
Prosand Cons for the application
Flywheelsare known to possess a power efficiency that is high it providescoupling for the load mechanically and because it does not utilizeany chemicals that are hazardous in nature it is environmentallyfriendly. The proportionality between the system efficiency and theelectronics and machines used power efficiency is direct. Nowadays,any regular machine has an 85% efficiency and above near 90%. Powerelectronics efficiency nowadays goes beyond 95 percent. Flywheels arepreferred to batteries because the flywheel system has a longer lifethan batteries (Neeteson, 2006). They can live for as long as twentyyears and above as long as maintenance is carried out regularly. Theyare stronger, faster, smaller, and lighter- typically, kinetic energyis calculated as velocity squared times mass. Therefore, doubling themass will significantly double the stored energy while quadrupleenergy storage will be attained by doubling the rotational speed.This makes them more advantageous since they are lighter and morecompact thus spin faster and maximize the energy density. Theflywheel is not affected by temperature changes.
Theflywheel can be a danger in the aspect of health as well as safety.Safety problems arise due to the hampering of the accumulators on theflywheel by the hazard of explosive destruction of the hefty wheeldue to overload. The flywheel has a primary limitation, and that isthe tensile strength of the material used for making the rotor. Thedisc may attain a faster spin if the disc is stronger and with thatthe system also stores more energy. Shattering results from exceedingthe tensile strength of a flywheel and this leads to a one-timerelease of all the energy stored in it. This is known commonly as"flywheel explosion." It is because fragments can reachkinetic energy that can be compared to that of a bullet. As a result,traditional flywheel systems demand that containment vessels arestrong enough as a precaution for safety. Safety hazards are referralto systems whose motor rotation attains speeds of more than 40,000rpm. For systems with a relatively low speeds of around 1400 rpm,there are no risks of shattering at all. Health and safety problemsresult from flywheel explosions mainly
Foryears, motor-generator pairs have been used as a way of separatingloads from disturbances by electricity supply. Flywheels were blendedinto these systems so that the rotary inertia may increase and as aresult, a period of distress that is tolerable. Integrated deviceslike these utilized only a small fraction of the kinetic energystored in a flywheel and, in general, provided a second ofride-through capability at most (Rockman, 2004). There are more usesof the flywheel that are more effective in applying quality of power.Some use required some ways to disconnect the kinetic energy that isstored in its rotating mass from the demands of electricity of theserved load. Adding a speed drive that varies, inverter and rectifiercomponents to the system provides a solution technologically althoughit is an expensive, cumbersome method. The advancing properconversion and technology control, integrated with a creativeintegration of the components identified above, have been keys todeveloping the technology. Flywheel generators are used in storage ofenergy, and the energy is the one used in various applications likein systems for launching aircraft, where aircraft use flywheels toproliferate energy supplied by the ship`s power so that it releasesrapidly into the electromagnetic launch system of the aircraft (Laan,2013). Other applications include motor sports and amusement rides.Also the storage of grid energy and in wind turbines (Mishra, 2006).
Theflywheel energy project has been an advantage in the sense that itadds much to the knowledge of engineering by challenging researchersto keep looking into the issue and in prompting the people inquestion to minimize hazards (Lindeburg, 2015). The project combinesknowledge from both electrical and mechanical engineering. Itincludes electric machines, control and mechanical design, and powerelectronics which is helpful in widening the scope of knowledge inthe fields mentioned. Power electronic components are the mostimplemented in this project. The choice of the machine used tooperate the flywheel system improved the knowledge in machines anddrives (Siedband, 2000). The model by Gray is a challenge to allengineers to consider saving costs for more energy storage and widentheir scope in the use of cheap alternatives.
Theproject was mainly a discussion of the flywheel energy storagesystem. It was a basic inclusion of an energy flow system that istwo-way in nature allowing energy to be pumped into the flywheel in aform of kinetic energy, then from the machine propelling the flywheeldrawn as electric energy. There are alternatives for the componentsneeded in the building the flywheel system. The system cons and proshave been discussed and the needed components selected depending onperformance, cost and reliability. Charging the flywheel can be doneby the use of a source of energy that is renewable or a directcurrent source that is from a grid. After charging, the flywheel candischarge its energy inclusive of a direct current voltage out of themachine. The direct current decaying voltage is available for use tothe boost converter that works to uphold a constant voltage of 220Vat the inverter input. The load is supplied by the inverter output.PIC microcontrollers carry out control schemes. Comparisons have beenmade to other alternatives in different aspects including costs,safety, efficiency and the aspect of health. Gray`s model has provedto be an efficient and cheap way of storing more flywheel energy.
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