HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
REGISTER   |   LOGIN   |   HELP
Blogs
Blog

Superbattery: The Next Great Triumph of Engineering

NO RATINGS
Page 1 / 3 Next >
View Comments: Newest First|Oldest First|Threaded View
<<  <  Page 2/8  >  >>
Kevin
User Rank
Platinum
Re: Redistribution of Energy Production
Kevin   2/10/2012 12:01:53 PM
NO RATINGS
Now play nice...Jerry.  One last time:

1.  7% transmission & distribution loss in the power grid (page 3):  http://www04.abb.com/global/seitp/seitp202.nsf/c71c66c1f02e6575c125711f004660e6/64cee3203250d1b7c12572c8003b2b48/$FILE/Energy+efficiency+in+the+power+grid.pdf

2.  One of the big benefits of hybrids is that they can use the electric motor to keep the gas engine running near peak efficiency most of the time.  This is in addition to regenerative braking and start/stop capability for the engine too.  Your technobabble is way off in the weeds.

3.  "in 1 yr the dirty, ineff coal plants will be gone or converted to biomass of NG".  Yeah...and we will have a 13,000 person moon colony by Newt Gingrich's 2nd term as president !

4.  Basically (in 8th grader's math): The EPA's MPGe equates 34 KWh of power out of the plug to 1 gallon of gas.  While this is indeed equal to the chemical energy of this amount of gas, it took about 3 times that much fuel energy (at the power plant) to create that much electricity.  If we could "mine" electrons directly, this might be a valid method...but not in this world. 

5.  I agree - Electricity is relatively cheap, mainly because of subsidies and the fact that Coal and Natural Gas is cheaper than Oil.  If we all changed to EV's, electricity prices would go up (supply-and-demand) and also it is only a matter of time until those fossil fuels get more scarce too.  Even with the relatively low cost of electricity, it takes at least 10-15 years to "break even" financially with an EV vs. efficient ICE car.  For example, the ~$20K price premium for a Volt would buy over 5000 gallons of gas.  At 40 MPG for the gas car, this is 200,000 miles to break even with the Volt, even with ZERO cost electricity!  You could also spend an additional $30K for a rooftop photovoltaic system to charge you EV - and have "free" electricity...but you'll probably never recoup that investment before the EV is worn out.

Anyway, it's clear that this conversation is not going anywhere with you.  The article's point (and I must say -  Charles Murray's articles are always great!) was about Super Batteries.  Any my point was - don't bother with putting these into EV's....let's put this technology into helping the grid become more "green" by buffering Solar and Wind generation.

Kevin

Jerry dycus
User Rank
Gold
Re: Redistribution of Energy Production
Jerry dycus   2/10/2012 5:26:34 AM
NO RATINGS
 

          You should sue your schools as they didn't teach you basic reasoning skils. 

          Since you built performance engines what was their SFC in lbs/hphr at 2000rpm outputing 10hp as a car at 55mph is likely to do?  What about while idling? Notice anything?  You can only use an engine eff at acceleration which normally is only a % or 2 of engine running time. No? Most driving is using under 10hp to the road and if using 10hp just to turn over the engine from friction, etc, what is the SFC/road hp?

          You can provide links to mpg sites all you want and I agree with what  they say on eff in a constant run engine at peak eff.  Sadly you seem to be incapable of understanding part throttle eff in real life which is FAR different and as you say you want, reality.

           I noticed you didn't put any links to FF grid % as you probably know by now I'm right on it.  I get daily updates on all grid, oil, coal, NG, EV, Auto, etc news, info from industry sources  You need to be up to date as it's changing very fast for the grid.

            As for using coal powered EV's in 1 yr the dirty, ineff coal plants will be gone or converted to biomass of NG, even with power from them EV's make less pollution and CO2 than similar ICE's by a good amount.  From RE or NG it's many times better EPA, website. And as I said before, most EV buyers also make or buy RE.

            EPA also shows eff and well to road total energy for each fuel of all types both car and grid.  But basic eff knowledge allows one to do ones own math. 

           Your misinformation on EV mpge is just plain wrong as is the way EPA counts it in their mileage rates.  

            I'm more into eff than EV's. Just EV's is by far the most eff way to transport people.

             And if my EV isn't eff then why does it only cost me $.005/mile for fuel? How much does your example Prius use?  Why?  Things you need to reseach before you spout such misinfo.  Someone who was not anti-ev would.

             I joined this list because I wanted to learn more from expert designers, engineers yet I find far more ignorance by supposed  EE's-ME's and others.    It seems I have to teach others just basic physics which with my 8th grade education shouldn't be!!         

Kevin
User Rank
Platinum
Re: Redistribution of Energy Production
Kevin   2/9/2012 6:24:50 PM
NO RATINGS
Jerry,

This isn't about my qualifications, but since you asked: I've built my share of performance engines and designed a lot of systems with electric motors too.  I'm both a degreed ME and EE and am deeply interested and knowledgable about alternative energy.  Don't get me wrong - I am 100% for getting us off of fossil fuels and promoting renewable energy.  In fact, that is WHY I have researched these issues quite extensively, and found that reality is quite different than what the popular media and EV zealots would like it to be.

So...to clarify my position - I am NOT anti-EV, but I am pro-truth and pro-reality.  Every factoid in my prior statements is completely true and verifiable, whether you are open-minded enough to learn about it or not.  You are being very loose and fast with the spec's you are mentioning - please see if you feel the same way after ANALYSING the facts.

Here's a smattering of some info that might get you started down the road to understanding these issues more completely.  Hopefully you can see that I'm not distorting anything, just pointing out reality.  I make no apology if reality does not align with preconceived notions.

http://www.green.autoblog.com/2011/04/24/toyota-targets-45-thermal-efficiency-for-engines-in-next-gen-hy/

http://www.transportation.anl.gov/pdfs/HV/2.pdf

http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption


http://www.designnews.com/messages.asp?piddl_msgthreadid=241083&piddl_msgid=536744#msg_536744

One thing we probably all can agree on is that we will eventually need to get off of fossil fuels, and it would be better to start earlier rather than later.  However, I believe EV's are a "head fake" and have little to do with this, since ~70% of power generation today in the USA (higher in most other countries except for France) comes from burning fossil fuels. 

I think it is more practical to put our efforts and dollars into efficiency and converting the power grid to renewable sources and creating a renewable fuel to replace gasoline.  Once the grid is mainly renewable based, EV's make more sense (how many decades for that to happen?)  and if the renewable car fuel is created - there would then be no NEED for EV's with all of the cost / range issues, etc. that they have, and no additional burden on the grid.

Just my informed opinion.  Regards,

Kevin


Jerry dycus
User Rank
Gold
Re: Redistribution of Energy Production
Jerry dycus   2/9/2012 5:30:38 PM
NO RATINGS
 

    I forgot the EV numbers.    An EV motor/controller is about 80-90% eff and only uses power when needed. It's only losses are bearings, unlike an ICE running it's cams, water/oil pumps, valves, alt, etc

  Since it needs no transmission no losses there. Battery charging is about 90% with 2-4% line losses, not 7% and the rest charger losses

  So it comes to power sources.

  RE at 100% eff -15% motor/controller-5% charging so about 75-80% eff to the diff. 

Old coal at 30% eff-25% so EV 22.5% eff

NG cogen 60% eff so  EV 45% eff

 Diff and wheels are about 20% losses but common with ICE.

I design, build both electric, wind and ICE vehicles for 40 yrs . What's your background?

Jerry dycus
User Rank
Gold
Re: Redistribution of Energy Production
Jerry dycus   2/9/2012 5:16:34 PM
NO RATINGS
 

   Kevin, a little knowledge is a dangerous thing.

  I stand by my numbers and EPA agrees with them as do most honest others.  where are you wrong? Let's count the ways.

 Sorry but Prii's are no where near 38% eff, about 10% in real life.  And it almost never runs in it's eff range even as a hybrid.

I was talking about power to the road. Real eff for ICE is very bad because just idling either at a light, coasting, braking all the while an ICE uses 5-10hp just to turn the engine over.  I can go 70mph on that much power in my 2 seat sportwagom EV.  Next the transmission weight, 5% loss.  Since an ICE is only eff at 75% plus power, it rarely hits that.  Most of the time running it's making none to 15hp which is only 10% or less eff. If you can't understand that you have problems.

Coal plants are dropping like flies with about 100 annouced closures over the last few months because simply they kill people with 30k/yr deaths in the US from them.  Presently we use about 43% coal and dropping fast.  By 5 yrs when any number of EV's are out there, only the most ef, c;lean coal will be left and that under 25% of US grid.

Personally I'm about to produce a 2kw windgen that can power an eff 1000sq' home and a light EV or 2.  This installed will be about $5k and give power for 50 yrs.  PV panels are now only $1.5k/kwhr or less retail, sunelec.com, so for about $1k I can charge my EV's for 25 yrs.

And it's being replaced by cogen NG units, 55-60% eff and RE, 100% eff most people consider.   Most EV'ers use RE either making their own or buying it. 

So I drive to town for $.15  and you can keep wasting your money if you want but stop spreading such bad misinformation.  Just google would have turned up your grid numbers being so wrong.

Kevin
User Rank
Platinum
Re: Redistribution of Energy Production
Kevin   2/9/2012 2:03:14 PM
NO RATINGS
Jerry,

Gotta love your enthusiasm, but you need to do more research before spewing wildly incorrect specs.  The statement "In vehicles the eff engine of choice by a very long ways is E drive as in the car gets 20-65% of the fuel's energy to the road VS 35% eff ICE's that only get 7% of their fuel to the road because they almost  never run at eff levels, wasting most of their energy. This is why I get 250-600mpg equivalent in my EV's vs 40-50mpg in similat ICE's." is nonsense.

The best ICE's are ~38% efficient (Prius, etc.) and in hybrid cars the engine is kept near the efficiency sweet-spot most of the time.  EV's "MPGe" comparison is complicated and there is much mis-information out there.  The average coal power-plant is approx. 32% efficient, and loses 7% for transmission loss, and then the EV has losses with battery charging / discharging / motor control and electric motor.  Net-net, an EV actually uses MORE energy (from the power plant) than an efficient fuel-burning car burns as chemical energy (as oil).  100% fact.

Now, to be fair - the grid is powered by various sources, varying by location and only ~50% Coal overall, 20% Natural Gas.  The higher percentage the grid is powered by renewables, the more the "green" benefits of EV's.  However, with today's grid there is basically ZERO energy benefit (actually negative benefit) on average, except that we shift from burning oil to mainly burning Coal + Natural Gas.

The MPGe of EV's, if calculated scientifically and honestly would be about 1/3 of the EPA sticker value.  In other words, the LEAF's 99 MPGe would actually be ~33 if related to how much fossil fuel it uses.  Your 250-600 MPGe figures are pure fantasy...

Regarding Superbatteries - I agree with some other posters that the best focus (near-term) would be buffering wind and solar power to the grid, NOT automobiles.  Autos are one of the most challenging applications imaginable, but a fixed power grid buffering installation could be large, heavy, have high initial cost and the utilities would be willing to amortize costs over decades. 

For autos, the best short-term solution is efficient conventional ICE's and hybrids, medium-term would be to create a renewable synthesized fuel that can take gasoline's place.  For urban cars, plug-in hybrids might make sense, but for most people the extra battery capacity is just a waste of money vs. conventional hybrids.  In other words - the VOLT would be more practical if it had a battery of half the capacity and lower cost and weight, and a MORE efficient gas engine - more like the Prius. 

Kevin

soessex
User Rank
Iron
Re: Battery technology
soessex   1/31/2012 10:20:21 AM
NO RATINGS
To GlennA:

!. Of significant importance, the flywheel has little velocity when not in use and when in use the vehicle is rolling to a stop.

2. The 100 pound weight was only selected for purposes of comparison with vehicle weight and could be much smaller as KE=1/2 MV^2.

3. Please investigate Porsche, F-1 and other KERS technology as flywheel speed above 40K are being utilized with very small flywheels.

GlennA
User Rank
Gold
Re: Battery technology
GlennA   1/31/2012 9:12:16 AM
NO RATINGS
John Jones

I have only skimmed through your (copious) calculations.  The magnetic / induction coupling sounds like an excellent innovation.  I did note at one point there was a 100 lb flywheel spinning at almost 9,000 rpm.  I assume the flywheel is mounted horizontally so that the gyroscopic effect doesn't prevent the car from turning corners.  This is only perception, but while I am not concernd about a motorcycle engine at 5,000 rpm, I do have reservations about a 100 lb flywheel at 9,000 rpm.  I wonder if it is only me, or if others would also be leery of this.

To the other readers:  Would you have any concerns, founded or unfounded, about a 100 lb flywheel spinning at 9,000 rpm under the hood of your car ?

soessex
User Rank
Iron
Re: Battery technology
soessex   1/30/2012 7:54:51 PM
NO RATINGS

 

SOUTH ESSEX ENGINEERING

 

Much of what ypou have posted is not accurate so gere is some additional information which gives details of a hypothetical test application. In this hypothetical the flywheel speed is exceedingly modest yet the energy stored is potentially substantial. Keep in mind the section which notes that the KE is a function of the square of the speed. I trust you will find this of interest. 

 

How it works: This system utilizes a flywheel, an induction mechanism and an overdrive transmission, among other things. The induction device is based on well developed existing eddy current technology and is envisioned as two independent co-axial, shaft mounted, bearing supported, shaded male and female rotating mechanical sections separated by an air gap, encompassed within a coil, operating on the principles of induction resulting from a controllable electric current across the coil. As noted later herein, a friction device could be substituted but with less efficiency. The electric current to the coil is varied in proportion to demand which instantly governs the strength of the flux density across the air gap between the rotating sections. The higher the current voltage to the coil the higher the flux density becomes and the greater the attraction across the air gap between the shaded parts. And, thusly, the throughput of torque is instantly set to any level from zero to full unit rating with no friction losses or the need for other parts. The great advantage to this is that this feature meters the throughput of the torque by enabling the two halves of the induction device to rotate at their own speed while transmitting torque between them as a direct function of controlled magnetic flux density (read voltage).

 

While in an operating range in the power-from-the-vehicle flow direction, the input torque to the induction device is always greater than or equal to the output torque. The induction device in concert with the gear system provides controllable torque variation without waste between this energy source, which is at a higher level, to that of the load, the flywheel, which is at a lower energy level. By varying the flux density (voltage) the level of transmitted torque can be instantly managed and controlled in real time.

 

 

When the energy flow is reversed, that is, from the flywheel to the vehicle, the issue is that of speed inasmuch as the over-drive gearing now acts as a speed reducer and a torque multiplier. As noted, the charged flywheel operating range is fast as compared to the vehicle operating range which is slow. Therefore, in order to accelerate the car, high torque is needed not high speed. The coupling of the induction device to the gear system performs perfectly to transform the high speed of the flywheel into the torque needed to accelerate the "heavy" car and therefore must be operated on a speed priority basis. Again, the induction device, through control of the flux density via voltage supervision, provides for this requirement. It should be recalled what the basic problem is the fact that the source energy in either power flow direction has its speed retarded while the receiving mass has its speed advanced. The key is that by increasing the voltage across the coil of the induction device we can change the overall effective gear ratio. Therefore, as the source slows the induction device via increasing flux density seamlessly changes the gear ratio the system sees.

 

Functioned off the vehicle's brake and throttle systems, the device conducts fully managed torque levels in each direction. As triggered and controlled, the induction traction feature of the device provides for variable and controlled power to and from the energy storage flywheel; and provides for, in effect, an infinitely variable transmission of power, first in the direction of the flywheel system (as a load) to store energy and subsequently, reversing the process, back from the flywheel system to the drive wheels of the vehicle (as a load).

 

Let's look further into the overall "gear ratio" of this system. The largest ratio available from the ground to the flywheel would be in a lock-up condition between the car wheels and the flywheel. Assuming the induction device is locked up; this would be axle rpm times differential ratio (1 to 3.5) times the overdrive gear ratio (1 to 6) which is 21 to 1. Say the induction device voltage is adjusted in stepless increments so that a series of output speeds, as a percent of input, are realized through the induction device. We first have: (given) 21 to 1 at 100%, and at 90% we have 18.9 to 1, at 80% we have 16.8 to 1, at 70% we have 14.7 to 1, at 60% we have 12.6 to 1, at 50% we have 10.5 to one, at 40% we have 8.4 to 1, at 30% we have 6.3 to 1, at 20% we have 4.2 to 1, at 10% we have 2.1 to 1, and so on.

 

Now, if we take a similar look at only the overdrive gear ratios combined with the induction device we have: 6 to 1, at 100%, 5.4 at 90%, 4.8 to 1 at 80%, 4.2 at 70%, 3.6 at 60%, 3 to1 at 50%, 2.4 to 1 at 40%, 1.8 to 1 at 30%, 1.2 to 1 at 20%, and 0.6 to 1 at 10%, and so on. In practice, being that the induction device acts as a traction machine, the actual ratios realized will be a function of many factors, but the effective result will be the same, seamless uninterrupted energy flow.

 

To visualize the system in action let us look at what takes place:

Car is traveling at some speed.

The flywheel is idle.

The speed differential between the car interface element and the flywheel are at a maximum.

The driver intends to significantly slow or stop the car and applies the brakes.

(The system works to slow the car as though the brakes were actually applied. Panic braking overrides the system.)

The system energized the induction device in proportion to the magnitude of the brake signal or call.

The induction device or modulator throughputs a torque in proportion to the call which rises from zero on a sine wave curve form.

Eventually, a peak ratio begins to descend across the modulator, say from hypothetically 50 to 1, which engenders a high torque because of this high slip angle, a condition well known in the field.

The car begins to slow and the flywheel begins to accelerate.

As a result, the speed differential is caused to lessen across the modulator, closing the ratio and decreasing the transmitted torque

If desired, the driver compensate by increasing the brake signal (call). 

The voltage at the coil is thus raised by the system controls.

The flux density is raised across the modulator.

An increased torque is reestablished which again spreads the speed ratio across the modulator which raises output speed to keep it progressively ahead of the flywheel speed. Within limits, these last few steps are automatically repeated over and over by the system so long as transferable energy is available and a call is maintained across the modulator. The more aggressive the call the more aggressive the energy transfer, speeding the flywheel and slowing the car. A similar process is applied to recover the energy from the flywheel. However be reminded that the gear ratios become somewhat reversed while the objective is the same. Now from this it may become visible just how the system changes the effective gear ratio. It can also be seen that the combination of the induction device and the overdrive gearing form an infinitely variable transmission able to smoothly manage output power under all conditions.

 

Some analytical calculations follow, and this analysis will include only certain aspects of the filed patent application in order to reduce the need to explain each element of a fully functional installed system. These omitted aspects while conducive to a workable system do not add to a clear understanding of the energy-transformation mechanism.

 

For this analysis we present a hypothetical automobile, supported flywheel, gear system and induction device as a framework for discussion. The car has the following characteristics: weight, 3200 pounds, mass 99.38 slugs (see calculations); tires, 24 inches in outside diameter and circumference of 6.28 feet (see calculations); rear wheel drive w/driveshaft; rear differential gear ratio, 3.5 to 1; approximate drive shaft RPM at 15 and 30 MPH respectively: 736 and 1471 (see calculations); trial flywheel weight, 100 pounds (rimmed) neglect spokes, radius of gyration 0.5 feet, mass, 3.1 slugs (see calculations); trial gear box ratio 1 to 6; induction device, stationary coil eddy current clutch with DC excitation.

 

Assumptions and stipulations: such controls as required are provided; the system is appointed, installed, connected and arranged with all aspects that may be required in an actual working system; on demand, power flow is conducted from the car drive shaft (as a hypothetical point of system connection for the purposes of this trial analysis) into the induction modulator and from there through the overdrive gearing to the flywheel which is thereby  accelerated as needed; the flywheel stored energy is similarly  returned in the reverse path to reaccelerate the car. The induction device, as controlled, throughputs from zero to full torque rating; as noted, to facilitate calculation of energy transfer, car speed set points are arbitrarily established at 15 and 30 MPH with flywheel charging beginning at (44ft/sec) 30 MPH (car) and ending at (22 ft/sec) 15 MPH (car); 

 

Formulae and calculations:

 

For the car traveling in a strait line, Kinetic Energy, (KE) = ½ M V^2,

 

Where,   (M) = Mass = W/g = weight in pounds / gravitational constant of 32.2 feet/second^2;

 

where,   (V) = strait-line speed in feet/second

 

Car @30, KE = ½ (99.38) (44) ^2 = 96200 Ft-Lbs.

 

Car @15, KE = ½ (99.38) (22) ^2 = 24050 Ft-Lbs.

 

For the Flywheel, traveling in its circular motion, KE = ½ (Moment of Inertia) x (omega) ^2

 

where, Moment of Inertia = Mr^2 = Mass times radius of gyration (r) squared, and

 

where, in this case,  r = mean radius for the rim of the flywheel = 0.5 feet

 

M = mass =  W/g, (same as above), and

 

omega (w) = angular speed in radians/second = 2pi x revolutions/second, and

 

where, pi = 3.14159 ...

 

substituting: Flywheel KE = ½(m) (r^2) (w^2)

 

= ½(3.1) (.5) ^2(w) ^2, where omega (w), is yet to be determined.

 

Calculate mass for car and flywheel:

 

Car mass = W/g = 3200/32.2 = 99.38 slugs

 

FW mass = 100/32.2 = 3.1 slugs

 

Calculate circumference (c) of the car tire:

 

C = (pi) (D) = 3.14159(2 Ft.) = 6.28 Ft

 

Determine speed of drive shaft @ 30 & 15 MPH:

 

30MPH = 44 Ft/sec and 15 MPH = 22 Ft/sec  over the ground and

 

44 x 60 = 2640 feet/ minute @ 30 MPH,

 

and 22 x 60 = 1320 feet/minute @ 15 MPH

 

Now, find car drive wheel RPM:

 

If we take the FPM rates above and divide by tire circumference (6.28 Ft) we get axel RPMs:

 

2640/6.28 = 420.38 @ 30, and 209.92 @ 15

 

Convert this to driveshaft RPMs:

 

Recall that the differential gear ratio is 3.5 to 1 therefore:

 

420.38 x 3.5 = 1471.33, and 734.72 RPMs respectively at the drive shaft.

 

Converting to revolutions per second we have:

 

1471.33/60 = 24.52 RPS @ 30 MPH

 

and  734.72/60 = 12.25 RPS @ 15 MPH

 

Now, for flywheel KE (above), we need (w), omega, in radians/sec,

 

Multiplying RPS by 2pi we get:

 

12.25 (2) (3.14159) = 76.94 Rad/sec @ 15 MPH, and,

 

24.52 (2) (3.14159) = 154.06 Rad/sec @ 30 MPH

 

Now recall that the power flows through the overdrive gearing at a 1 to 6 ratio from the car driveshaft to the flywheel, and importantly in a 6 to 1 ratio from the flywheel to the car driveshaft.

 

Therefore, multiplying the above by 6 we get theoretical (assuming modulator at a1:1 final ratio) flywheel speed in Radians/sec:

 

76.94 (6) = 461.64 Rad/sec @ 15 MPH

 

 (Note: Flywheel RPM = 4408 (safe))

 

And,

 

(154.06) (6) = 924.38 Rad/sec @ 30 MPH

 

(Note: Flywheel RPM  = 8827.18 RPM (safe))

 

From above: Flywheel KE = ½(m) (r^2) (w^2) = ½(3.1) (.5) ^2(w) ^2

 

Substituting, we get:

 

(½) (3.1) (.5) ^2 (461.64) ^2 = 82580.7 Ft-Lbs.  @ 15 MPH equivalent shaft speed

 

And,

 

(1/2) (3.1) (.5) ^2 (924.38) ^2 = 331110 Ft-Lbs.  @ 30 MPH equivalent shaft speed

 

Analysis:

 

Recall that the energy of motion in the car at 30 MPH was a maximum of 96,200 Ft-Lbs and 24,050 Ft-Lbs @15 MPH. It is important to note that the system can store no more energy than that which is available from the source. In the subject example, we have presented a trial scenario which could if available store between  82,580.7 and  331,110 Ft-Lbs of energy.  In these trial calculations we arbitrarily selected a 100 pound flywheel and a 1 to 6 overdrive gear ratio. Either or both can be altered (lessened) in which case we would have less weight in the flywheel and/or less speed in the flywheel. Each of these present a favorable  design outlook. In conclusion, the subject system as assumed has far more capacity than needed under the assumptions offered. Massaging the numbers for a more perfect design is left here to others.

 

In this trial examination, the mass of the car was about 33 times the mass of the selected flywheel and what this flywheel mechanism does is manage energy transfer over time between these two masses.

 

A further review of how this system works helps one visualize precisely what is taking place when the system is in operation. Lets say while approaching a red traffic signal, the initial conditions would be the car traveling at some level of speed and the energy storage system in a dormant state. In preparation to stop the car the driver initiates normal braking action and the instrumentation of the storage system energizes the induction modulator coil in a direct relationship to driver input and the modulator outputs a proportional torque which turns the overdrive gearing and begins to accelerate the flywheel transferring energy from the car to the flywheel and thus slowing the car.

 

With certain exceptions, as long as the input shaft speed (source) to the energized modulator is greater than its output speed the flywheel will continue to be accelerated thereby storing more and more energy, and continuing to slow the car. Integrated system controls hold the friction braking process out of initiation unless or until prescribed parameters dictate their initiation. System components and controls isolate the flywheel from the remainder of the system when no further input torque is available in the cycle. That is to say, when the flywheel speed and the input shaft speed to the flywheel begin to approach the same rate as happens at the end of the charging process. Without completely stating the process the energy transfer back to the car is similar.

 

The function of the induction device is analogous to the friction brakes of an ordinary car or truck. With such friction brakes one aspect rotates while the other is fixed. When in operation a friction system attempts to lock the moving part to the stationary part which causes considerable disagreement between them turning the energy in the rotating part into the heat of friction. As with auto brakes, the subject induction device when energized causes an infinitely variable attraction across an air gap between its two halves but instead of one being free and one being fixed, both are free to turn although this turning is alternately resisted by the inertia of the masses attached to opposite ends of the system, one being the car the other the flywheel. In operation, the rate of transfer of energy in each direction is directly proportional to the level of excitation of the induction coil which is controlled by ordinary driver actions while monitored and supervised by system controls. While the calculations noted herein were based on 15 and 30 MPH earmarks, the actual usable operating range will be more encompassing. Importantly, as noted, flywheel speeds are low within the system as described.

 

Additional  calculations:

 

Let us consider what happens during a flywheel charging cycle using this system:

 

Let the cycle time be 3 seconds

 

First, we must recognize that the induction device is analogous to a variable torque slip clutch but without friction losses. For such equipment, the torque range is from zero to full name plate rating for continuous service but as much as 2 - ½ times name plate rating for intermittent service. The subject system is in the latter class. Regarding this induction modulator, it should be kept in mind that a friction device could be substituted for the induction unit.

 

So, to further explore this machine, let us select some reasonable level of torque within the range available to the machine. Arbitrarily, we pick 75 Ft-Lbs. This tells us that this is the amount of force coming through the induction device so long as the torque supplied to the device is greater than 75 Ft-Lbs. We don't know how much torque it takes to overcome the power flow disadvantage presented by the hypothetical 1 to 6 overdrive gearing so we need to make an estimate. Let us say 10 Ft-Lbs. (recall that no such losses are incurred when the power flow is reversed as the gearing becomes a 6 to 1 reduction drive,)

 

That leaves a net force to accelerate the flywheel of 65 Ft-Lbs. The cycle time is 3 seconds, the period to charge the flywheel and to slow the car before the friction brakes come into play.

 

Find the speed to which the flywheel is accelerated by this torque (L = 65 Ft=Lbs.)

 

First determine moment of inertia (I) for the flywheel:

 

Where m = mass, and r = radius of gyration

 

 I = 1/2 (m) (r)^2

 

m = 3.1, and r = .5 Ft

 

I = ½ (3.1) (.5)^2 = 0.3875 slug-ft^2

 

Now find acceleration for the flywheel:

 

Let (L) represent torque, (a) represent angular acceleration, and (I) represent moment of inertia

 

Where L = (I) (a), and a = L/I = 65/.3875 = 167.7 rad/sec^2

 

Now find the angular distance traveled (s) in the time (t) of 3 seconds:

 

(s) = wt + ½ (a) (t)^2,  when w = 0 rad/sec, s = ½ (a) (t)^2 = (.5) (167.7) (3)^2 =

 

 754.65 radian

 

Now find the final angular speed (V) of the flywheel:

 

The change in speed V, (omega2 – omega1) = angular acceleration (a) time (t)

 

with a in rad/sec^2, t in seconds, and V in rad/sec

 

V = (167.7) x (3) = 503.1 rad/sec

 

Then, flywheel KE = ½(I) (V)^2

 

Where: I = 0.3875 slug-ft^2

 

 Then, KE = ½ (0.3875) (503.1)^2 = 49040 Ft-Lbs

 

Find flywheel RPS and RPM:

 

Where Rev/second = radians/sec / 2pi, and rev/min = rev/sec x 60

 

 503.1/2 pi = 80.1 rev/Sec, or 4804.2 RPM)

 

Now let us attempt to visualize what result we get when we return this energy to the car. We will assume that the system components are arranged in the most advantageous configuration.

 

The energy drained from the flywheel is fully controlled by the induction device; this modulation of the available flywheel energy gives full control of the available energy as to rate and duration and thereby quantity. This exceedingly high degree of control provides seamless recovered energy application to re-accelerate the car up until the car speed equals the equivalent proportional residual flywheel speed exhausting the transferable energy and completing the return cycle. During this return cycle, the passed energy goes through the 1 to 6 gearing which lowers its speed and raises its torque. This is of great importance as the ratio of the involved trial masses is about 33 to 1, as noted above. It is obvious that for the system to work this disparity in mass has to be accounted for and it is; when the receiving mass is low the system provides the speed needed; conversely when the receiving mass is high the system provides low speed and high torque required to motivate the greater mass of the car.

 

 

 

Very truly yours,

/S/

JOHN JONES, PE

President of South Essex Engineering

 

GlennA
User Rank
Gold
Re: Battery technology
GlennA   1/30/2012 8:57:05 AM
NO RATINGS
soessex;  The flywheel is a very interesting concept.  Although I don't know how practical it would be.  The momentum of a flywheel is in the spinning mass.  So to capture the momentum of a 2,000 lb vehicle, you either need a heavy, fast spinning toroid, or a medium-heavy, really-fast spinning toroid.  And a 500 lb toroid / gyroscope spinning at 5,000 rpm will affect the handing of the vehicle.  The energy capture / re-use would be good while driving, but after parking for several hours the captured energy would be lost to bearing friction.  Then the flywheel is 'dead weight' that adds to the mass that needs to be accelerated.  I guess an option would be a 'plug-in flywheel' that has a small electric motor to counter bearing friction to keep the flywheel spinning.  I think batteries may be better than a flywheel for overnight energy storage, but the flywheel concept still is an interesting option.

<<  <  Page 2/8  >  >>
Partner Zone
More Blogs
These are the toys that inspired budding engineers to try out sublime designs, create miniature structures, and experiment with bizarre contraptions using sets that could be torn down and reconstructed over and over.
PowerStream is deploying the microgrid at its headquarters to demonstrate how people can generate and distribute their own energy and make their homes and businesses more sustainable through renewables.
Printrbot unveils its all-metal Printrbot Simple, bringing durability to low-cost 3D printers.
Today's robots should be respected, and humans should be wary of their growing skills and sophistication. Quite simply, robots are better than us in a lot of ways. Here are 10 of them.
Product design is changing with advances in technology and outsourced manufacturing. The Art of Product Design spells out the future of design engineering.
Design News Webinar Series
3/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
2/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
12/18/2013 Available On Demand
11/20/2013 Available On Demand
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Apr 21 - 25, Creating & Testing Your First RTOS Application Using MQX
SEMESTERS: 1  |  2  |  3  |  4  |  5


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: April 29 - Day 1
Sponsored by maxon precision motors
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service