pronstar

GE recently unveiled a locomotive that's closer to the hybrids we see on the road. It uses regen braking to capture and store energy, claims benefits of up to 15% reduction in fuel use, and 50% lower emissions.

Here's the link:
http://ge.ecomagination.com/site/products/hybr.html

Scotty

Off topic but a question...where can I find a way to use my Cummins as a generator instead of hauling one around? Might as well get something out of it that way too.
I recall there was a pulley driven generator of sorts. It would be nice if the power fails at the house that I could fire up the Ram and plug in the house.

Scotty

sled4fun

I have not been under my truck for sometime. Don't remember if it has a PTO off the transfer case or not. Need about a 6kw to run most things in the house until you get into an A/C unit. Then you need about 12-15kw min.

johnny5.9

I'm not trying to hijack this thread but while on the topic of hybrid technology and fuel savings, has anybody thought about the idea of a MDS (multi displacement system) in a diesel? The idea would be to shut down cylinders when not needed to produce power. The only problem I see with this is the larger amount of reciprocating mass in diesel components versus gas. This, I think, this would make the vibration a big issue. Also the heavier components not being used to produce power would decrease the efficiency of the cylinders that are still functioning, possibly to the point of being counterproductive. Has anybody heard if a company is toying with this idea? If it could be done it would certainly make for some good MPG.

RJ285

I am just restating what I have been told. They took a hummer 6.2L diesel that got less than ten miles per gallon and with the hydraulic transmission it gets close to thirty and they doubled the torque at the wheels.

97% is just the transmission, not taking into account the engine and it's losses. Maybe the number is wrong, but even 90% is really good.

sled4fun

I have wondered if that was possible myself. I know Chrysler is doing that with some gas V8's, but gas engine have compression braking and by holding valves open at certain times and killing cylinders this removes the pumping ability of those cylinders and under a light load will increase fuel economy.
I don't know if diesels will gain as much if any increase in economy.

Dartmouth 12V

Doing a series style hybrid is not as efficient as the series/parallel hybrids that are available. This is because once you are at cruise, you are converting chemical energy(fuel) to rotational energy(engine) to electrical(generator), back to rotational(electric motor). Once at cruise, it is more efficient to run without the electric system assuming that you are running approximately in the right rpm band. You are essentially taking out two energy conversions which both have inefficiencies. The reason that hybrids are so good is the startup. Electric motors are great for getting things going since they don't need a clutch and they can deliver a lot of power quickly. This means that the engine needs to be smaller so it will be more efficient. A combination of series and parallel hybrid systems would be better.

As far as motor size goes, I would think that they would need to be on the order of 100KW continuous. My ford ranger electric is 25KW and it does pretty well but it is a lot smaller. Most of the electric drive systems don't run over 300V so you are looking at 330A continuous with peaks of 2000A or more. The wire gauge on it would have to be enormous.

As stated earlier, most of the testing of this sort of thing has been done by military groups. They have done a lot of testing of hummers that are hybrid. I know that they saw much better fuel economy but I don't have any numbers.

farmer0_1

i always wanted to build a 100hp tractor with a diesel electric. when i win the lotto.

edwinsmith

A good setup would be to have a bank of NiMH rechargeable batteries to provide acceleration torque and to use regenerative braking to recharge the batteries on deceleration. A much smaller engine running at peak efficiency could be used to supply recharge power also. This would be somewhat like the current crop of hybrids which use both the engine and the batteries to drive the wheels. The engineering is in the tradeoffs between battery weight, performance and efficiency. More powerful motora and more batteries means more fun. Smaller motors fewer batteries makes more economy. The engine is sized to provide the right amount of recharge to make up for drag and heat losses and power accessories.

Building such a vehicle would be fun for somebody with the money and the knowhow or you could just go buy a hybrid and be done with it.

Edwin

dodgeguy71

GM's been doing that for at least a year(in gassers). Having V8's that cut out cylinders and become 4 cylinders under certain conditions and I think they have an inline 5 cylinder in one of the SUV things, I think it's a 5 cylinder but it does that too. I went to school on it and it did not get rave reviews from us mechanics, looked way to over thought, complicated....to many moving parts to fail. Not sure how it has done though. I got out of the business a little over a year ago when they were first coming out with it. As far as diesels if you held the valves open on the cylinders you did not want to fire, but you'd have to turn off the fuel somehow so not to wash your cylinders down.

farmer0_1

gm gassers have had the 4-6-8 tech for 20 years cadillac has been using it for most that time.

Raspy

I'm not a big fan of dropping out cylinders to increase mileage. On the new Honda Pilots, for instance, that technology only gives a one MPG increase over the standard engine. It does nothing to reduce the internal sliding friction.

Turbo diesels, by their very nature, are variable displacement. More boost equals more displacement and more power. So the weight and internal friction of a small engine can put out the power of a big engine. Diesels use less fuel at light loads than a gas engine and don't have the high intake manifold vacuum. So dropping a couple of cylinders for economy doesn't make much sense. Just reduce the fuel delivery even farther and make the engine as small as possible. Just big enough that at maximum boost it will hold together and produce the required power. Then the low power economy takes care of itself.

Hybrids have better fuel economy in town, I think, because the engine is off so much of the time and there is a small gain from regenerative braking. On the road they get what might be expected from a very small engine in an aerodynamic car. They could do so much better if they had more battery power and a way to judge the trip length. They go a very short distance before starting the engine, over and over at stop lights. If they could be told the trip will be only a mile the engine could stay off, for example. But the way they are now the car doesn't know if you are heading out on a thousand mile trip or just to the corner. Plug in hybrids may fix this and many are hacking their Prius systems to do just that.

One final technology that may eventually get here is electric valves. This will be a major breakthrough in automotive engine design. No more camshaft, cam belt, rockers, etc. No more throttle because the valves can do that. And perfect valve timing for maximum torque at any given speed. If you want to drop out cylinders for economy just program it in and randomly choose the ones to drop. Easier starting because it can spin and then add compression. Built in engine breaking, just program it. The list goes on and on. Including a lighter and more compact engine size.


John

RollOver Pete

Do diesel/electric haul trucks have large battery banks?
If I remember right, makers like Unit Rig, Wabco, Lectra Haul and Dart had diesel generators, traction motors, and electric motors to supply hydraulic pressure for breaking, steering and raising the bed. Many were stared by compressed air. There was no room for large banks of batteries.
Why wouldn't something like this but on a smaller scale work in a 1 ton Dodge/ Cummins powered truck?

farmer0_1

keep it coming i am enjoying this thread. i don't think the big strip mining trucks had any battery pack.

johnny5.9

I love the idea of electric valves. The idea makes so much sense that I'm surprised we don't see it yet. Formula 1 cars use pnematic valves and turn 18500 RPM, that may be a way to go. The programmable jake brake from the factory would be sweet.