Nemesis8

iTrader: (3)

Regenerative braking comes to internal combustion engines. Shep Technologies in UK have applied their system to the Lincoln Navigator. The results were as follows on the test vehicle:

Brake Life increased to 77%
Fuel Economy Increased by 38% (13MPG to 18MPG)
HP increased by 85 HP to its dead stop acceleration (275 HP to 360 HP)
Dirty Emissions were cut by 50%

The company is tight lipped about when consumers can see this technology on production cars.

Wow - add that to our driveshaft!

saturn

This is kinda misleading. The Prius and Insight have regenerative braking and they have combustion engines. The concept of regenerative braking has nothing to do with the engine at all. It all has to do with where the energy is going to be stored and what it's going to be used for. The hybrids use it charge the electrical assist batteries. I think the Navigator is using a new approach with hydraulic storage that uses hydrolic pressure to help accelerate the vehicle.

Interesting idea, but not really big news. Just another hybrid-esque technology that's finally getting some play because of all the notoriety of gas prices and such.

dupa12345

hydraulic storage, eh? must be a lot lighter than batteries

Nemesis8

iTrader: (3)

Correct - it has three major components: A pump, a tank, and a controller. The motor-pump attaches to the driveshaft. The pump "grabs" the spinning driveshaft to slow the vehicle during braking. The pump transfers the energy to a unitized accumulator, a hydraulic tank that stores pressurized fluid. Energy is sent back to the pump, helping it turn the driveshaft when the vehicle accelerates from a dead stop. An electronic controller uses software to determine when to run the pump and in which direction.

midlife crisis

What does the "pressurized fluid" act upon to store the energy? Fluids don't compress and store energy so the accumulator must be active in some way.

staticlag

fluids do compress

therm8

Fluids do compress, just not much. However, they can be pressurized greatly due to this incompressable property. That pressure is the stored energy. 3000psi of hydrualic pressure can do some amazing things. It's identical to electrical storage in principle. Driveshaft turns generator(pump), which charges battery(hydraulic accumulator/tank), which discharges to turn the now motor(turbine? I guess that's what the pump becomes in reverse).

I think the concept could be very useful in a variety of situations. From aiding economy due to "free" power for acceleration, to a burst of speed upon exiting a corner at the track. It's not nearly as productive as a gas-electric hybrid, but then it doesn't come with most of the hybrid's drawbacks either.

Nemesis8

iTrader: (3)

There is a website

midlife crisis

Fluids cannot store any useful power, only transfer it. That's why pressure vessels are pressure tested filled with fluid so they don't become shrapnel when they fail as they would if filled with gas.
Therm8's electrical analogy would be correct if you could store energy in a resistor.

r0tor

iTrader: (1)

Ford had a hydraulic assist drivetrain on a show truck about 5 years ago... think they called in HLA for hydraulic launch assist


Its a good system but there are some serious drawbacks. The accumulators can store much less energy then a battery system on an electrical regenerative braking hybrid, and the results of a 3000 psi hydraulic cylinder isn't going to be pretty when you get in an accident

therm8

If that were the case, a SuperSoaker watergun would not work. Large cranes you might find at a cargo dock would not work. Submarines would not be able to maneuver. Etc.

Using a pump to raise pressure in a closed fluid system stores the energy input from the pump as that pressure increase. Temperature will also increase as a result of the pump raising pressure.

Use a positive displacement pump on a full tank of water. Pressure will rise rapidly as you squeeze in more water. Now vent that pressure (with the pump off) to a water turbine and watch it spin. The work done on the system by the pump was "stored" as pressure, which when applied to the turbine, subsequently causes work to be done.

therm8

It could easily be rigged with an sensor like air bags use to open a relief valve in the event of an accident. I've seen a 3000# hydraulic rupture, and it's not pretty (particularly in an enclosed space), but in open air you'd merely have a mess to clean up. While it is more flammable in mist form, it should still have a sufficiently high flash point to not warrant a fire concern, and should be no more frightening than riding around with a highly volatile mixture of hydrocarbons under your trunk .

marvin_rock

I got lost at like the fifth or sixth post. You guys are SMART as hell! That is all.

saturn

They've talked about using all manner of storage systems for regenerative braking for decades. They've just been worried about the development and maintenance costs as well as what happens during accidents.

Some sort of electric launch assist in the 8 would probably be very useful for pwning n00bs. Leave the high revving rotary alone and just get the low-end grunt from batteries instead of FI. Dunno how plausible it is, but that certainly would **** of the muscle car fans who think louder is faster.

Nemesis8

iTrader: (3)

As for the Shep system, this looks very promising, but I bet they only offer it for the gas hog suv's of the World, where they could protect it better with all that framework under the body.

dupa12345

i like this .. batteries are heavy period

gas compressing cylinders can be probably made very light weight .. they can also be small and applied directly to each one of the wheels .. heck even multiple ones .. now how do you apply that energy in a linear manner so it actually propels the car rather then just blow tires of the wheels?

i could definately see that in a sports car .. especially if you could put some cylinders on the non-driving wheels and use the second set of tires to increase traction

saturn

What the hell do you think "turbo boost" is? They've had this technology since the mid-80's on a Trans Am. Gotta be big oil keeping this from being commonplace.

SSJ 909

Dude granted im just reading about it now, but..

Brake Life increased to 77%

Fuel Economy Increased by 38%
that means we would get like 25- 32 mpg!

HP increased by 85 HP...
Lets say if the rx8 got even half that. 40 more hp is all good!

Dirty Emissions were cut by 50% saving the enviroment...
I think this would be a sick step in the right direction, you are basically improving the car by like 50%

SSJ 909

btw is there a way to have the company modify this to your car, or is the price/procedure just to crazy?

r0tor

iTrader: (1)

the range of flashpoints for hydraulic oils ranges from about 400 deg F to about 1000 deg F with the stuff on the higher end being seriously nasty stuff that easily breaks down into a base and can cause cancer (called Frequel oil or something like that). Its found in a lot of steam power plants on hydraulic actuators near steam lines.

You do make a point about riding around with a gasoline bomb. I'd have to think the odds are in the gas tanks favor though on probability of rupture (and we know those do rupture from time to time).


I agree venting could keep you from blowing up, but the atomized fluid would catch fire on the exhaust and I'd be interested if the enviromentalists would let you dump oil out of your car on purpose.

midlife crisis

Gee, the physicists and engineers I work with don't agree with you. They do say that fluids are very slightly compressable but all agree that there would be virtually no storage in a fluid other than what is normally thought of as a gas.

Just try using your SuperSoaker with no air in the pressure bottle - IIRC they call for 30% air to water ratio when pumped up.


Cranes and subs use hydraulic TRANSFER of energy not storage. Those cranes have engines running pumps to move stuff. Same in a Sub.
You may want to read the entire article in howstuffworks.com but here is a quote:

"Hydraulic systems simply transmit forces from point to point through fluid. Most systems use an incompressible fluid, a fluid that is as dense as it can get. This sort of fluid transmits nearly all of the original force instead of absorbing some of it. The most commonly used incompressible fluid in hydraulic machinery is oil. "

Another site would be vessac.com a manufacturer of hydraulic accumulators where they show cut away views of their piston type accumulator 3K PSI and drawings of their bladder type that goes up to 5K PSI. Both use a gas to STORE the energy.

therm8

Potential energy...

The incompressibility of water is what gives it the ability to "store engergy" as pressure. I've worked on a submarine. Guess what. Those pumps don't run all the time. Only to repressurize the system below certain setpoints. However there air aircharged accumulators involved, so you are right in that it was not a good example. Under heavy loads the pumps will run more constantly. I'll give you the crane one, because I don't know much about them.

My question to you, then, is...What causes the driveshaft to spin after the tank is pressurized? It takes energy to do work. Energy was used to pressurize the tank on braking. Then possibly several minutes later, the pressure is released to turn the driveshaft. You could call this a transfer of energy, but if you want to get technical, everything involving energy is a transfer.

I have pressurized small solid systems of water using an air pressurized hand pump. When the pump is disconnected. There would be a few thousand psi of pressure in that system. Wait ten years and open the valve, and water comes blasting out. I'd call that storage of energy. It's not much different than carrying something up 10 flights of stairs and waiting 10 years to push it off the edge.

The problem in this debate is that most people are used to dealing with air pressurized hydraulic systems. The only example I have really personally seen, I can't discuss due to the nature of my job. It is extremely easy to pressurize a full tank of oil (without the use of anything but more oil). Granted the storage capacity is less than the air pressurized ones, but for quick storage and release (as in this driveshaft application) air pressurized oil doesn't work as well as a solid system. The drawback is the very high pressures achieved, but that is also an advantage.

I'm starting to ramble so I'll quit now.

midlife crisis

which would you rather be in a room with when the top breaks off it:
1) a high pressure cylinder of nitrogen
or
2) an identical cylinder at the same pressure filled totally with water

I know my choice!

Renesis_8

Both would kill you haha, but the gas tank would probably kill others around you too!

or ... both would kill everyone.. haha
________
Vaporizer video

therm8

2 of course.

which would you rather be hit in the face with:
1) a 1" hose ejecting nitrogen from a 100psi tank
or
2) a 1" hose ejecting water from a totally filled 100psi tank?