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FLYWHEEL Energy Storage Systems

Discussion in 'Technical Discussion' started by brian eiland, Apr 21, 2010.

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  1. brian eiland

    brian eiland Senior Member

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    Flywheel Energy Storage Systems ( .....verses latest battery systems?)

    Storing electrical energy has always been a real problem,….how to do any large quantity, in a compact manner, and how to be able to extract (and charge) it quickly. It’s a problem that begs for solutions, and some of those solutions will take us forward into a new energy future for the world….storing energy beyond the ‘chemistries’ of burning fuels and electrical batteries.

    Years ago I became aware of some research work John Hopkins Applied Physics Labs was doing on flywheel energy storage systems. This was really in its infancy when the spinning flywheels were big weighty chunks of metallic material, and the vacuum chamber problem was important primarily to delay frictional decay of the spinning wheel rather than its more important roll now.

    My interest in boats was gaining momentum at this same time, so naturally I though of replacing the aux generator set and battery bank onboard many cruising vessels with a hi-tech flywheel energy storage device. I think it was somewhere around 1971-72 I made such a dwg for a 50’ catamaran that utilized a single diesel engine mounted in one hull that hydraulically powered two retractable prop drive units in each hull, and spun up a sizable flywheel energy storage unit in the opposite hull. Thus only one primary diesel engine was required for the whole vessel. Electrical requirements for the vessel, including the starting of the main engine were all handled by the energy stored in the flywheel device. Of course there would be at least one emergency battery for starting purposes, just as there are backups in ordinary vessels.

    Alas, through many years of attempts to bring this flywheel technology to fruition, there continued to be two primary stumbling blocks standing in the way of real time deployment of this relatively simple idea of storing energy in a spinning disc:
    1) Our past is littered with energy devices that never made it mainstream as their full potentials were not pursued due to the significant cost involved when compared to the existing cheap fuel/oil energies….no need to be so energy/cost concerned, so why bother spending research/development monies here.
    2) Maintaining a vacuum chamber for the spinning wheel to be housed in, combined with proper bearings for its support, just never really got solved, particularly as the wheels went from metal chunks at relatively slow speeds to carbon fiber wheels spinning upwards of 60,000 rpm, and there needing to be some mechanical connection/communication to the outside of the chamber.

    Now there comes a company (combination of companies I would say) that believes they have solved these major problems that have hampered deployment of flywheel energy storage devices. They believe they have solved the vacuum chamber problem by providing a hermetically sealed chamber for the flywheel itself, and a communication with the outside world via an innovated magnetic gearing and coupling mechanism in the form of continuously variable transmission CVT. This CVT appears to have evolved from the Formula One (F1) motor racing, and their latest desires to recover their significant ‘braking energies’ and use them for acceleration once again. There are claims of 99% efficiencies with this coupling. This promises to put flywheel energy storage devices back into contention with the most promising and greater notoriety new battery storage developments. Flywheel energy storage possibilities are BACK into the picture ! HURRAY !!

    I say this with a mighty ‘Hurray’ as I once did when Chrysler first announced its development program to put a flywheel powered race car into the Le Mans competition. I’m excited once again.

    So here are a few reference articles to visit for more details:

    1) Wheels: The Science of Spin,… Flywheels
    This was my source of news of this latest development in this technology. It’s called “DESIGN fax”, and is available for subscription.

    2) Making a Case for Flywheel Energy Storage
    Uses include ‘frequency regulation’ in our electrical power grid, and the Navy’s use to launch aircraft on a next generation carriers.

    3) Torotrak and Xtrac Toroidal Variable Drive CVT
    Compact continuously variable transmissions for use in the new kinetic energy recovery systems (KERS) proposed for Formula One motor racing.


    ** Note: Both the flywheel energy storage technology, AND the variable transmission technologies could find some applications onboard our vessels.

    Attached Files:

  2. brian eiland

    brian eiland Senior Member

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    Wheels: The science of spin — flywheels

    High-speed flywheels are a cheap and efficient way to hybridize systems from cars, elevators, and industrial machinery to inter-city trains. Yet until now their development has been hindered by the lack of a robust way to transmit the power to and from them. Jesse Crosse reports on some ingenious new developments at Ricardo.

    Designing products which consume less energy has shot to the top of the agenda in this energy-hungry world — not just in the automotive business but in any industry delivering mechanical products which do work for our benefit.

    Recovering kinetic energy from objects that have been accelerated, and then re-using that energy, is one way of cutting consumption. For example, when a vehicle is accelerated from rest by the engine, the kinetic energy in that vehicle is usually wasted when the time comes to slow down, either through frictional losses and aerodynamic drag when coasting, or heat when braking.

    In electric vehicles, this energy can easily be recovered and re-used by using the electric drive motor as a generator to slow the vehicle, generating electricity in the process. In cars, this electrical energy is typically stored in a battery or ultra-capacitor and then re-used when the driver wants to accelerate again, whereas in rail applications electricity can be fed back into the power distribution system via the overhead catenary or conductor rails. However, another and potentially much more cost-effective method, not just for electric vehicles but for those powered by traditional combustion engines as well, is the flywheel.

    Flywheels make great children’s toys in the form of spinning tops, gyroscopes, and yo-yos, but they are also hugely effective energy storage devices. Decelerate a car by energizing a flywheel rather than wastefully using the brakes, and the energy it stores can be used the next time the driver wants to accelerate.

    Hybrids, Formula One, and flywheels
    Ricardo has substantial experience in flywheel hybrid system development. It has investigated many different kinds of energy recovery technologies such as ultra-capacitors, hydraulic systems, electric flywheels, and mechanical flywheels — including the engineering of kinetic energy recovery systems (KERS) for Formula One applications. As a result of this work, Ricardo has devised "Kinergy," a compact, lightweight, high-speed, hermetically sealed flywheel energy storage system concept with a highly innovative and patented magnetic gearing and coupling mechanism.

    Modern carbon fiber-based flywheel systems such as Kinergy can typically operate at speeds of around 60,000 rpm. With consequent outer surface speeds of around Mach 2, a vacuum is essential, as friction from any surrounding air would cause the carbon fiber to quickly overheat and de-laminate.

    The high power density and long-life potential of Kinergy technology results from its inherent simplicity and effectiveness, avoiding the need for vacuum pumps and seals and offering a robust, compact, and lightweight package. The simplicity of its design also yields comparatively very low projected production costs, thus opening the door to a wide range of potential applications.

    The technology appears ideally suited for application in passenger cars ranging from small, price- sensitive mass-market models to large luxury SUVs, enabling the effective hybridization of a wide range of applications where conventional electro-chemical battery systems would be prohibitively expensive. Potential additional Kinergy applications also include low-cost, compact energy management and storage systems for use in industrial and construction equipment and local electrical substations and power distribution systems.

    Scalable energy store
    A flywheel is a relatively simple energy store. It is scalable, modular, and has a high power density, which means it can absorb and release energy very quickly. Unlike battery systems, with their much higher energy density but much slower ability to absorb and release it over time, modern flywheel systems are thus much closer to ultra-capacitors in operation, making them ideal for delivering short bursts of power, such as during acceleration.

    Flywheels are hence, in effect, a complementary technology to batteries, but in an electric hybrid powertrain they offer direct competition to ultra-capacitors, out-scoring them in terms of cost, volume, weight, efficiency, and ease of manufacture. A battery has to be sized for energy capacity, power, and the number of charge and discharge cycles it can withstand. But with the Kinergy system, a continuously variable transmission (CVT) determines power output and the flywheel speed. Both can be optimized to achieve the balance of power and duration of output needed.

    Although this approach is entirely mechanical, the flywheel can also be connected to an electric motor-generator and electrical system. It could also be connected to a hydraulic displacement unit rather than a CVT.

    Flywheels are extremely versatile devices. In a conventional car, they can be used to seamlessly feed power back into the powertrain, reducing the work done by the engine, saving fuel, and reducing CO2 emissions. In a hybrid or electric vehicle, they reduce the drain on the battery, helping to extend the range.

    There are less obvious uses, too. Dual-clutch transmissions (DCTs) are becoming more popular because the lack of torque interruption provides the refinement of a torque converter automatic gearbox with the relative simplicity, efficiency, and packaging benefits of a conventional manual gearbox. The simpler alternative to DCT, the automated manual transmission (AMT), is much cheaper to manufacture and equally efficient: however, it suffers from torque interruption during gearshifts, which often led to poor levels of refinement in fully automatic mode.

    Ricardo has a patent pending on a flywheel system which can fill the torque gap as the gearbox shifts. “The system is the same cost as a DCT and just as refined,” says Ricardo technical specialist Andy Atkins. “However, because of the added hybrid function, it delivers a 20% reduction in fuel consumption as a bonus.”

    High-energy applications
    Beyond the passenger automotive sector, larger units are perfect for use in trucks, buses, and passenger trains which continually accelerate and stop. “Kinergy is tailor made for trains,” Atkins continues. “The braking energy of a TGV (bullet train) or large express train represents a huge amount of energy. For example, braking from full speed to rest, a modern high-speed train dissipates about 0.9 gigajoules, which is the energy equivalent of 90 liters of diesel fuel. In this application, Kinergy flywheel systems would energize as the train brakes to a stop and give back their energy as they help to accelerate it away from the station. Recapturing up to 60% of the energy available on each occasion, Kinergy technology fitted to a high-speed train could deliver energy savings of the equivalent of about 75 liters of diesel for each station stop.

    Flywheels can improve the efficiency of elevators, too. An elevator full of people on its downward journey could store enough energy in a flywheel to allow a lighter passenger load to make the next upward trip for free. Yet, as with any spectacular new technologies, there are some myths surrounding flywheel systems mainly derived from old-fashioned heavy steel flywheels.

    Modern devices used in hybrid drivetrains are quite different, explains Atkins. “As Kinergy shows, modern high-speed flywheels can be very small and lightweight. Flywheels only need to be heavy if they are spinning slowly. The idea that they have a detrimental effect on handling is also a myth; as you increase the operating speed, inertia and gyroscopic forces are reduced for a given energy storage capacity. They have no more effect than taking a passenger out of a car.”

    Manufactured from carbon fiber wound onto a metallic hub or directly onto a shaft, these modern flywheels spin in a vacuum, typically at speeds of around 60,000 rpm. A vacuum is essential. With a surface speed of Mach 2, friction from any surrounding air would cause the carbon fiber to quickly overheat and de-laminate.

    Powertrain integration
    Flywheels are usually integrated directly into a powertrain; one example being the rear axle of a rear-wheel-drive car. The Kinergy flywheel system incorporates a small Torotrak continuously variable transmission, through which torque passes to the flywheel from the driveline, then smoothly from the flywheel back into the driveline whenever required. The huge rotational speed of the flywheel must be reduced before its power can be transmitted to the driveline. One way of doing this is by conventional gears, but at those speeds there are issues of frictional losses, wear, lubrication, the transmission of vibration, and foreign bodies finding their way between the gears.

    Some of the original motorsport designs were like this, harvesting and delivering torque via gears — a system that, although acceptable, has drawbacks for everyday use. A shaft leaving the vacuum chamber passes through a seal which inevitably leaks slightly. The faster the flywheel spins, the more the seal leaks, necessitating a vacuum pump to maintain the vacuum and introducing the need for maintenance. So Ricardo came up with a better idea, a magnetic gear which allows torque to be transmitted from inside the vacuum without penetrating the seal.

    The magnetic gear can be configured to give a reduction of 10:1, so if the flywheel is revolving at 60,000 rpm, the output shaft can revolve at 6,000 rpm, significantly reducing windage losses. Magnetic gears use permanent magnets to transmit torque through an airspace between two shafts, without the need for mechanical contact.

    Ricardo’s system comprises a rotor on the output shaft of the flywheel rotating inside a cylindrical rotor on the power-take-off shaft. An array of permanent magnets is set into each, and it is the attraction between the magnetic fields of these magnets that links the rotation of one shaft to another.

    One inherent difficulty in engineering this arrangement is achieving close enough proximity of the magnets for the principle to work, given the thickness of the casings. The peak field distance is at around a millimeter, so the optimum distance between the two arrays of rotating magnets would be around double this — not enough to maintain an acceptable air gap and casing thickness. But installing ferrous pins in the casing wall transmits the magnetic field and the wall effectively disappears, allowing acceptable air gaps to be incorporated within a comfortable engineering tolerance. Efficiency is extremely high at more than 99.9%, and the system is robust, too. In the event of a serious torque spike, there are no gears to shear. Instead, the magnetic connection will slip and is quickly re-instated by simply backing off the torque.

    Safety factor
    Achieving a sufficiently high safety factor in such high-speed components is clearly important. Kinergy’s carbon fiber flywheel has a margin of 12 times the ultimate tensile strength (UTS), or in other words, it is being stressed to one-twelfth of the UTS of the carbon fiber material. The design is such that failure modes can be detected by the automatic monitoring of out-of-balance vibration by bearing sensors, enabling safe shut down before further consequential damage is caused. In the worst case, the external casing would, in any case, contain any failure.

    The major challenges will come with mass production, says Atkins. “Although relatively cheap to make in principle, winding the filament onto a bobbin is relatively time consuming. This means that increasing volumes in the production process may be a challenge.”

    Yet Kinergy is cost effective, and it is estimated an entire unit integrated with a differential could be made for around $1,500. The flywheel and CVT represent about a third each of the cost, with the differential and other equipment making up the rest. The unit would be substituted for the standard differential, so there are savings to be made there, too.

    Bearings are the only limiting factor, and in practice these will ultimately decide the service life of the unit. The current state of the art is to use ceramic balls and steel races: these already last the life of the system. The only service requirement would be to reinstate the vacuum, as the composite material used to make the flywheel seeks to balance its own internal water content with the atmosphere around it and water will continue to "boil" out for some time.

    “This is all standard vacuum engineering practice, though,” says Atkins, “It’s a simple job which involves plugging in a vacuum line during a routine service. If we didn’t have the magnetic coupling, however, then we’d be doing that every couple of hours and you would need an on-board vacuum pump.”

    The rotating seals of a mechanically geared system would also wear, so the problem would get worse with time. Replacing these gears would involve a total break into the vacuum, with inevitable water ingress into the system and the pump would have to work a lot harder.

    To remove the need for any kind of maintenance, Ricardo has also developed a solid-state pump which would mean never having to do anything at all. Known as "getter" technology, Atkins explains that this currently highly confidential technology is extremely promising: “It absorbs just about everything except hydrogen in a physical rather than a chemical process,” he says.

    (Continued)
  3. brian eiland

    brian eiland Senior Member

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    Many potential applications
    The list of applications is extensive, concludes Atkins, since flywheels are ideal for anything that involves intermittent flows of high power. “Flywheels are particularly good for vehicles that stop often — and the heavier the better,” he says. “So cars, trucks, trains, trams, buses, materials handling machinery such as cranes and elevators and even White Van Man [English slang for work-van drivers], as it works brilliantly for delivery vehicles! They’re also good for electrical power management systems where highly intermittent demands need to be smoothed, such as local distribution grid or railway substations, in particular, for example, mass transit and metro power networks which are required to manage regenerative braking loads from rolling stock being fed back into the conductor rails or overhead lines.”

    “Ricardo’s Kinergy technology is inherently cost effective, robust, reliable, and compact, giving it a huge potential for many such applications. Its highly compact size and light weight also makes it an ideal candidate for aftermarket system integration without affecting the original equipment design, on anything that requires a pulse of energy,” Atkins adds.

    Without any doubt, the future looks good for flywheel technology. Proof comes in the form of the inquiries that are flooding in to the Ricardo offices as more people begin to understand that, when it comes to reducing energy consumption, few devices are quite so elegant in their simplicity, their efficiency, and their cost effectiveness, too.
  4. Grecko

    Grecko New Member

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    Flywheels are a way to store energy, but they haven't been used much for a variety of reasons.

    First of all they are not nor ever will be inexpensive. While you can make them from composites the amount of energy that you can store in a composite flywheel isn't nearly as much as one would think. The winding process is very delicate and in order to get high strength it takes a lot of care, so it will always be a time intensive and expensive process.

    While fiber composites fibers such as carbon or boron are very very strong, it is very difficult to disribute the loads in the windings such that you can take advantge of that strength. I was involved with an Air Force sponsored program designing, making and testing fiber reinforced titanium rotors for an advanced turbine engine. What we found was that the windings under the highest stress took all of the load and then broke, and then the failure cascaded through the disk, breaking each layer as they became the high stress one. Bottom line was that much of the advantages of the higher strength material was never going to be realized. Net result, conventional materials were about as good and didn't have brittle failure modes like the composites. A composite wheel with magnets on the rim for energy input and output sounds like a good idea, but again it is difficult to attach the magnets and transmit the loads effectively to the fibers. Also the magnets will get hot and the composites in a vacumn have trouble getting the heat out. This again limits the useful strength of the composites, since they don't like getting very hot. Also if the magnets get thrown from the wheel, they will be ejected like missiles, and once the first one goes, the rest will be out in the next millisecond.

    If you try to make the rotor from conventional materials you have a potential problem with low cycle fatigue that limits how much stress (energy) you can put into the wheel. Now it is common to see stress levels of close to 200,000 psi in the bore of a turbine disk, so you can see that the technology is there to use the material to store as much energy as it can hold. Also remember that while there are strong steels, the problem that they tend to be brittle. You absoutely need to have a material that isn't brittle, or you will have a low cycle fatigue problem and you cannot imagine how much energy is released if a disk bursts at high speed. For a conventional material, the casing that is needed to contain a potential disk burst is heavy, or if it is Kevlar, it is pretty big. I've seen a disk burst event where a three pound turbine disk spinning at 80,000 rpm came out of a tiny engine an would have killed anybody within 20 feet of the event. A big flywheel is trying to store thousands of times more energy than was in that tiny turbine... Think about it.

    There are going to be losses where ever you try to put a sealed shaft through the casing, and the more energy that you want to get in or out, the bigger the shaft needs to be. Bigger shaft, more seal drag.

    Flywheels work best for short term energy storage, like in a race car where you are storing a lot of enery for a very short time with high input and output rates. For a marine application they don't make nearly as much sense, since the parasitic loads will eat up the energy over time, and modern batteries are better for longer term storage.

    Also remember that the amount of eneryg storage that we are talking about here is really very small compared to hydrocarbon fuel. If you could store some energy you "might" be able to run the air conditioning overnight, or you might be able to make some small headway for a few hours, but anything more than that is not gonna happen with energy storage as we know it now.
  5. brian eiland

    brian eiland Senior Member

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    I might suggest you visit these two reference sites and have a look at the drawings and descriptions:
    http://www.ricardo.com/en-gb/News--Media/Press-releases/News-releases1/2009/Ricardo-Kinergy-delivers-breakthrough-technology-for-effective-ultra-efficient-and-low-cost-hybridisation/

    http://www.sae.org/mags/sve/7291

    Looking back at that article fron Racardo,
    "The major challenges will come with mass production, says Atkins. “Although relatively cheap to make in principle, winding the filament onto a bobbin is relatively time consuming. This means that increasing volumes in the production process may be a challenge.”

    Yet Kinergy is cost effective, and it is estimated an entire unit integrated with a differential could be made for around $1,500. The flywheel and CVT represent about a third each of the cost, with the differential and other equipment making up the rest. The unit would be substituted for the standard differential, so there are savings to be made there, too"

    That's not terrible bad. This is an estimate from a pretty well respected firm, so I'm hoping we are in the ball park.


    This is always a item to be aware of when we seek to 'reinforce' one material with another. Its happened numerous times when adding reinforcing carbon fiber to selected locations of a boat structure. The carbon fiber material is so overwhelmingly stronge that it takes all the load by itself while possibly not having been designed to do so. And the substrate material ends up failing as it was underdesigned in hopes that the addition of carbon fiber would add that needed extra strenght.

    Note that this carbon wheel contains no embeded magnets nor other foreign materials. Its pure carbon fibers on its outer perimeter. Those magnetic pieces making up the 'magnetic gear' are disposed to the two output shafts that are separated by an air gap rather than piercing the vacuumed containment shell. Those magnets that exist on the shaft connected to the flywheel are subject to much lower rim speeds than is the carbon flywheel. And spinning in a total vacuum there is no frictional heat build up.

    Granted it can be a poroble. But we built and operated a LOT of jet engine turbines that are operating up in these regions with all kinds of blades stiking out in space, and yet we don't have that many of those exploding. A number of experients with spinng carbon fiber wheels that were not embeded with any foreign materials, metals etc have simply 'fuzzed up' on destruction.

    There are NO shaft penetrations of the flywheel containment casing in their design. They've paid particular attention to this detail so will not have to deal with frictional heat build up in the flywheel material itself, nor supplying some aux pumps tec to maintain this vacuum.

    No parasitic loads in an absolute vacuum.

    No doubt its going to be tough to compete with hydrocarbon fuels, but also remember we need to be comparing apples to apples. When you talk stored energy comparisions, remember the energy in that flywheel is ready to use. The energy in that fuel must be created into a usable form by burning it, and in that process we lose more than 50-70% of it to heat lost.
  6. brian eiland

    brian eiland Senior Member

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    Formula 1 Racing...Kinetic Energy Recovery Systems

    The rule changes we're most interested in are those concerning the introduction of the Kinetic Energy Recovery System (KERS) that will eventually make every future Formula One race car a hybrid. KERS is not mandatory in 2009 but will be in 2010 and as a result some teams who have no chance of challenging for the world championship have opted not to use KERS immediately. To remain competitive in 2009, the usual race winning teams will all be running KERS this weekend and for the full season.

    The FIA rules governing KERS are fairly simple but very restrictive. From this season teams are allowed to use KERS to draw 60 Kw of energy from the rear axle on the car, which can be stored up to a total of 400kJ (111 watt hour) of energy per lap, to be reused in the form of a 'boost' button. In effect the system uses regeneration to collect and store energy during braking which allows the drivers to use 60 Kw (82 hp) for 6.6 seconds per lap. The teams are free to choose between either mechanical or electric hybrid systems. Of the ten teams in Formula One, all bar one have chosen the electric hybrid system with only Williams pioneering a flywheel mechanical system.
    ........

    .....Williams have decided to take on the task of being the only team in the field to develop a flywheel system and to do so without the resources of a major manufacturer behind them. Williams will run Toyota engines, but more on Toyota in a moment. They acquired of a minority shareholding in Automotive Hybrid Power Limited, a company developing high-energy composite flywheels for use in energy recovery systems. The Williams Hybrid Power system will use a flywheel spinning at up to 40,000 rpm. It has been reported that the flywheel systems is still being bench tested and has not been track tested as yet. This may result in Williams not debuting their KERS until Round 7 of the 2009 world championship which takes place in Turkey in early June.

    http://www.gizmag.com/formula-one-kers/11324/
  7. brian eiland

    brian eiland Senior Member

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    Boeing's Flywheel Work

    An overview of Boeing flywheel energy storage systems with high-temperature superconducting bearings:
    http://iopscience.iop.org/0953-2048/23/3/034021/pdf/0953-2048_23_3_034021.pdf
  8. brian eiland

    brian eiland Senior Member

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    Volvo is working on KERS flywheel tech

    Volvo Car Corporation, Volvo Powertrain and SKF want to re-capture the energy that's normally lost as heat during braking and use it to reduce fuel consumption by up to 20 percent. Need a quick shot of muscle? Volvo's Flywheel Kinetic Energy Recovery System (KERS) is hooked up to the rear axle to augment the conventionally driven front wheels with up to 80 horsepower to the back tires. This technology isn't new, but this consortium's implementation is the first time a system like this has been fitted to a car's rear axle while a conventional power unit drives the front wheels.

    The KERS system's quick buildup and dissipation makes it most effective in urban driving, which, conveniently, is highly inefficient. The flywheel is made out of carbon fiber and spins in a vacuum at speeds up to 60,000 rpm. That stored energy allows a four-cylinder-powered car to step off the line with more authority, and since it's a through-the-road style system, a complex and expensive torque-split device isn't needed to reap the fuel economy benefits of supplementing (or even shutting off) the gasoline engine at opportune moments.

    Volvo shows off KERS flywheel tech [w/video]
  9. PropBet

    PropBet Senior Member

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    Is Everything!
  10. brian eiland

    brian eiland Senior Member

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    Another Electric Powered Race Car

    Not a flwheel energy storage one, but electric drive and regeneration

    Drayson Racing Technologies and the Lola Cars group have just revealed what is intended to be the fastest electric-powered racing car in the world. The Lola-Drayson B12/69EV features Drayson's brand new 4X2-640 electric drivetrain, inductive charging, composite battery power, moveable aerodynamics and electrical regenerative damping. Its four electric motors are said to deliver a whopping 850 horsepower and a top speed of around 200 mph

    ...more here:
    Lola Drayson B12/69EV electric racing car launched

    Attached Files:

  11. carelm

    carelm Senior Member

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    Brian,

    The first production car application for a KERS system might be the Jaguar CX16. The concept car has a 380 hp supercharged V6 and a supplemental KERS system that delivers an additional 95 hp. It can also be driven below 50 mph on electric power alone. To the best of my knowledge, Jaguar has green-lighted the car including KERS for production in the 2013-2014 timeframe.

    Mike
  12. brian eiland

    brian eiland Senior Member

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    Audi's Hybrid System uses a flywheel for energy storage

    AUDI R18 E-TRON QUATTRO WITH WILLIAMS HYBRID POWER TECHNOLOGY MAKES STRONG START IN WORLD ENDURANCE CHAMPIONSHIP

    audi_motorsport-1.jpg

    Williams Hybrid Power designed an entirely new, ultra-lightweight electric flywheel and associated power electronics for the Audi R18 e-tron quattro, delivering 150KW of power with a top rotor speed of 45,000 rpm. The key benefits of the WHP system are a high power density and correspondingly low mass, the ability to continuously deep power cycle, high efficiency energy transfer to and from the e-storage, and an insusceptibility to performance or life degradation over a wide range of operating temperatures. These defining features are highly suited to endurance racing and made the WHP flywheel the prime candidate for Audi’s project when compared to other technologies such as batteries, ultra-capacitors or mechanical flywheels.

    http://www.williamshybridpower.com/news


    ....one key to the newer flywheel technology
    "The next evolution was electrically-driven flywheels which do not require a CVT system thus avoiding added weight and reduced efficiency. Electrically-driven flywheels have another important advantage over their mechanically driven relatives in that vacuum integrity is easier to maintain as no high speed mechanical seal is needed. WHP's MLC flywheel is electrically driven."


    **********************************************
    Audi hints at production plans for flywheel tech

    http://www.just-auto.com/comment/audi-hints-at-production-plans-for-flywheel-tech_id123019.aspx

    ***************************************************




    This weekend, Audi’s R18 e-tron quattro hits the track at the World Endurance Championship (WEC) in Spa, Belgium. Not enough that the race car is powered by a V6 diesel engine. It also uses a flywheel as energy storage. Why should we care? Audi makes noises that this technology could soon show up in production cars.
    Says just-auto:

    “In the R18, a V6 diesel engine sends drive to the rear wheels, while for the front axle, the energy is electrically recuperated and fed into a flywheel. This can then be returned to the front wheels during acceleration. Of interest here is that Audi has chosen this technology over batteries. Why? According to Wolfgang Ullrich who heads up Audi’s Motorsport division, even the most advanced cells would have been too heavy.”

    Ullrich says that this it not just tinkering with race toys:

    “I can safely state that the things we’re testing with flywheel energy storage are of interest to our production colleagues too. The combination of different systems is an aspect that will have to be considered in various applications in the future.”

    Audi: Vorprung Durch Flywheel? | The Truth About Cars

    ...more here
    Flywheel hybrid systems (KERS) | Racecar Engineering
  13. Grecko

    Grecko New Member

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    The key advantage of flywheels systems, as used in KERS applications is that they have a high power density. That is, they can be discharged and recharged at very quickly without damaging the hardware. In these systems they can do this at higher rates than chemical systems without thermal runaway. All that is great when you are dumping in and removing energy 6 to 10 times in a two minute lap. In these systems you are storing energy for only a few seconds, and using it right away, the next time you accelerate.

    Storing a usable amount of energy (high energy density) for long time is a whole different bag of cats. When you look at powering a boat (which has a much higher and sustained energy requirement) its simply better to store energy as a fuel and use it when you need it.
  14. brian eiland

    brian eiland Senior Member

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    Please realize that I am NOT suggesting that this flywheel stored energy be utilzed to power the vessel itself, but rather I had suggested it might be a substitute for the traditional diesel powered gen set, and/or big battery bank....for silent aux power.

    I'm also keeping track of this technology as it has held a long time interest by me. So when I find new developments with respect to subject I try to post them here.
  15. Kevin

    Kevin YF Moderator

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    The big advantage of a flywheel system is quick charge and discharge time. In racing, they use regenerative braking, etc to quickly run up the flywheel and then discharge it just as quickly to accelerate. The braking energy would otherwise be wasted, so using it in this manner is an efficient means of taking something that would be thrown away if it wasn't being stored up

    In big boats there's no means of quickly regenerating the power in the flywheel (you don't stomp on the brakes every few moments) so to charge the flywheel you'd have to be spending something else.... fuel. If you're using fuel to charge the flywheel, it defeats the purpose.
  16. brian eiland

    brian eiland Senior Member

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    Quick charge and discharge is but one positive attribute, but certainly not all.

    Have you looked at the potential small size of these flywheel energy storage packages?....potentially quite small. Or the packages that might utilize the very small micr-turbines that are being developed concurrently. If you could replace a big diesel aux generator set with one of these??

    What wouldn't allow you to charge up these flywheels slowly during the normal operation of the main propulsion engines. We don't have to use 'regenerated power' necessarily.

    The flywheel device is just an energy storage medium that is a smaller, lighter
    'package' that can deliver electrical power for our vessel in a quieter manner. And it is more efficient in accepting its charge, and more efficient in delivering its stored power,.....at least that is the potential.
  17. brian eiland

    brian eiland Senior Member

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  18. brian eiland

    brian eiland Senior Member

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  19. karo1776

    karo1776 Senior Member

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    Power production and Roll Stabilization.

    Brian:

    Nice to see Ricardo Engineers mentioned here. Sir Harry's company is one of the leading development sources for thermo-machinery and now-a-days energy use. Recommend his autobiography.

    First some background:

    A long time ago my graduate paper in electrical engineering was on hybrid propulsion... long long before it became popular. The idea proposed was a directly coupled turbine and permeant magnate brushless alternator / flywheel assembly producing wild voltage and frequency power which was converted electronically and powered PM motors. The turbine was operated in a pulse mode (pulse turbine) with PWM fuel control which could be turned off or on as power demand required. The motors on the load could act as generators for regeneration such as braking in a land vehicle. Basically feeding power back to the power plant which could be stored in a flywheel in combination with the rotating mass of the turbine wheel and generator.

    The PWM fuel control was developed by my very good friend and mentor Warren Boardman at Marquardt Corp in 1957 for use in pulse rockets.
    Warren invented pulse rockets, Pulse width modified fuel control, spy satellites, multiple reentry technology then known by the acronym, PAT-C, PAT-C standing for position, attitude and trajectory control also, fortuitously matched President Roy Marquardt’s wife’s name, Patsy. Warren and Marquardt pioneered many other important technologies... actually have a video of running a small diesel engine on a pulse rocket injection system as a test bed back in 1957... the fundamental of modern modern pulse width modulation PWM electronic control fuel injection. Warren by the way never got much credit as much was classified. The bigger project was developing the digital electronic control in the analog age... although transistors had been developed by Bell labs in the early 1950's by John Bardeen and Walter Brattain using germanium doped crystals... applications only developed slowly. It took about 200 engineers to do the engineering development of the pulse rocket... after Warren's Advanced Development group proved the concept.

    It was PWM control ideal applied to the situation as it could minimize chemical energy consumption and control such to very fine limits... actually without it Apollo would not have been possible (Warren did the initial flight profile concept and convinced the newly formed NASA of it which resulted in the success you know so well... very interesting story as is the spy satellite or "Mount Palomar in the Sky"). Interestingly, the smallest rockets controlled the program literally and figuratively... not the big main engines. Actually, many of the diesel and spark ignited electronic fuel controls now-a-days are based on this fundamental technology. It has become universal in efficiency of any streaming but incrementally variable process control... where fine control is necessary.

    Unfortunately, the motor technology when I did my studies was not quite there. We had sumarium cobalt magnets and built motors with them. This had been used in some satellite and missiles of various types. However, the problem was usually heat transfer out of the stator. Much later in the late 1980's and early 1990's Joe Denk at Allied Signal invented his toothless motor technology which solved the problems of increasing magnetic density of the machine and cooling it. But I had moved on.

    Problem:
    However, I think an energy system like this would be very applicable now-a-days in land based vehicles and any start and stop operation. But for boats I don't know. Generator systems typically produce to relatively stable power loads... and the propulsion systems the same. As pointed out before its not a start and stop situation... just one big constant energy draw... .


    Solution:
    However, the idea of combining the flywheel somehow with the energy production of the yacht as a means of roll stabilization does have much merit. These functions could be combined with the somewhat variable load needed for electrical supply. Actually and interestingly, roll control and space attitude control are similar where a limit cycle and energy input minimization situation are paramount. Here is a demo of gyroscopic roll stabilization on the Wally Ace... towards the last 1/3 of the video.

    WallyAce 26m from Motor Boat & Yachting - YouTube

    But the idea of PMW control does provide the improvements in fuel consumption of the diesel and spark ignited engines with electronic injection now so universal the industry.
  20. brian eiland

    brian eiland Senior Member

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    Why the Patriot Project Failed

    ...big excerpt from the very first posting that started this thread

    Photos of the Chrysler Patriot race car are there...#1

    Now I found several explanation's by some of the principles involved as to why this project never went further forward. Ian Sharps's is particularly interesting

    Chrysler Patriot hybrid-electric racing car