Posted on 09/07/2008 2:34:28 PM PDT by saganite
I play paintball and my compressed air tank is regularly charged to 4500 psi. I shoot the gun just like a rifle, with the tank nestled right under my face. I’m not worried.
Only 25%? Given the start-stop usage I would hope it would be greater than that.
Correct, and the article suggests that’s where the low hanging fruit is with this technology. Doubling in city mileage would be huge for companies like UPS etc.
This is the first step. Here’s the para that shows where the technology is headed.
Other hydraulic hybrid designs are still in the prototype or even simulation stage. The most radical tend to be full-series hybrids, which completely do away with a mechanical transmission. And that makes perfect sense. The biggest potential for fuel economy gains and emissions reductions seem likely to come from power train designs that can break the mechanical link between the engine and wheels — something parallel hybrids like the Toyota Prius do not do. With the engine load decoupled from the road load, the engine can continually be run at or near its maximum efficiency point. Dr. Carsten Breitfeld, BMW’s manager of power train development, said as much in a speech given late last year at the CTI Innovative Transmission Symposium in Berlin. Throw in the potential of full-series hybrids to capture braking losses and allow significant periods of engine-off operation and they become even more attractive from both economy and emissions standpoints.
What, the private sector came up with this without any government money? It’s impossible.
You don’t seem to get. Hydraulic accumulators have been with us forever. I dare say that you will find more gas tanks that have exploded than accumulators.
Helium would be great, except that it is prone to leakage and conducts heat very good. It does pretty much comply with the perfect gas laws though.
All:
The reason this works is because although a standard mid size car may need 200 peak HP, 99% of the time it needs only 20 HP. Passing. tromping on it to get yourself out of a bad situation, etc requires the 200 HP. Most of your driving requires only a fraction. However the engine has to be sized for peak power to cover you when you need it.
The energy stored in the accumulator provides for the peak. Most of the time you are operating from the small power-plant. FYI, the same thing is being done with some electric vehicles.
Hydraulic?
Ummmmm. (scratching head)... Why does it need a spark plug at all?
Moonbat delusions. Storage at that pressure must require a large and very stout reservoir...
Hydraulic fluid used for propulsion is commonly compressed as high as 5000 PSI in farm and construction machinery. Compressed hydraulic fluid will not cause a conventional explosion due to it’s low compressibility. It is dangerous, in that a pin hole leak can cause a jet that will penetrate flesh, inject oil, and cause a horrible wound. If a pressurized vessel breaks, it just pops out some fluid and makes a mess, pieces do not fly all over the place. Compressed gas is the dangerous part and of course you have that in an accumulator.
Problem with accumulators on mobile applications is that you can’t compress enough volume of gas to get much range. I could see it working to recover braking energy then use it immediately to re-accelerate.
Also, hydraulic pumps and motors can only approach 90% overall efficiency, so a system with one of each will at best recover 80% of the available energy. And that does not account for whatever cooling loss from the gas occurs.
Back in my cubicle dwelling Dilbert days, I designed hydraulic components and systems for mobile machinery. Hydraulic drives are valued for their convenience, not their efficiency.
“The reason this works is because although a standard mid size car may need 200 peak HP, 99% of the time it needs only 20 HP.”
Question - I saw the discussion on using the braking system to recapture energy. Couldn’t they also utilize the shocks with one way valves to capture additional energy in that way as the vehicle tooled down the road, stopped/started?
How does a one-way shock return to it's neutral position? Can you see that a shock with a one-way valve would be a hydraulic piston jack, not a shock absorber?
Ahem. Not exactly. The EPA has had a big hand in development. However, wouldn’t you rather see your taxpayer dollars at work in something like this than community organizer training?
“Couldn’t they also utilize the shocks with one way valves to capture additional energy in that way as the vehicle tooled down the road, stopped/started?”
Good question... And the answer is yes. There have been several technical articles written about it.
Well, I’m guessing that VW has a gas engine that needs that spark plug. Even the perfect realization of this technology still requires a conventional engine of some sort. Even if that’s a diesel it would still need a glow plug.
I was thinking you could put a limit on it to only open the one way when the internal pressure was below a pressure equivalent to the spring strength. That energy is typically lost through heat in the shock rather than additional dampening. If the pressure created in the shock is less than the spring potential AND less than the pressure in the system then the valve would not be opened as the system would not require any additional energy OR the shock could not return to neutral.
While you might be able to gain incremental efficiencies with what you suggest I think the cost would negate the advantages.
Undrstand your point - I just like to think of these things as a steam cycle. A lot of people assuming it is more like a gravitational - one way thing.
Undrstand your point - I just like to think of these things as a steam cycle. The input for this one being the increased pressure during the bumps rather than fuel. A lot of people assume it is more like a gravitational - one way closed loop system.
that should read “one way open loop system” - doh
I’d rather not see taxpayer dollars go into either. I wasn’t aware the EPA was investing and while I hope it proves successful, I wonder how many other schemes the EPA has been involved in that didn’t amount to anything. The free market can do what it always does best, put capital into ventures that promise a return on investment.
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