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-   -   Are they developing locomotive-style diesel electric motors for cars? (http://www.genmay.com/showthread.php?t=837425)

Aldaris 08-07-2011 12:39 PM

Are they developing locomotive-style diesel electric motors for cars?
 
From my understanding, a diesel locomotive operates by using the big diesel motor to generate electricity, which is doled out to electric drive motors that actually propel the locomotive forward.

My question is, are there any late-stage or even early-stage developments that you are aware of, that would put this sort of technology in a car chassis? Chevrolet came very close with the Volt, except that the motor used to charge up the batteries and run the electric drive motors runs on gasoline - not on diesel. A diesel generator should be more efficient, right? It would kick on only when needed to charge up the battery and then shut back off, and it would provide extended range for trips longer than battery-only capacity.

Creepster 08-07-2011 12:59 PM

You lose about 50% power, when using it to charge batteries - letting a small efficient diesel running at constant rpm, feeding the battery "excess" energy to use when accelerating hard or for city driving is what i want.

You'd only need a small 30-50 HP'ish diesel, but IIRC, diesel scales down bad.

[H]ard|On 08-07-2011 02:17 PM

The efficiency of a generator comes not from diesel although that helps since the fuel itself is more energy dense, but from the fact that like creepster mentioned it sits there at some RPM in it's efficiency range. No varying of RPM needed, it just chugs nice and low.

So you answered your own question - the Volt is basically that. Never mind that it's gas - like I said diesel IS more energy dense by about 30% iirc, but it's also now more expensive than gas making that the same dick in the other hand, if you will, cost wise.

Gas engines scale down better, all the way down to a handfull of CCs - the only thing the Volt should change is the direct drive feature to become basically a pure electric road locomotive.

Fiah 08-07-2011 03:57 PM

[QUOTE=Creepster;24834440]You lose about 50% power, when using it to charge batteries - letting a small efficient diesel running at constant rpm, feeding the battery "excess" energy to use when accelerating hard or for city driving is what i want.

You'd only need a small 30-50 HP'ish diesel, but IIRC, diesel scales down bad.[/QUOTE]

Small diesels are relatively expensive, needing more expensive parts than gas engines of similar power. Big diesels are relatively efficient at delivering small amounts of power (at least compared to gas engines), so scaling down doesn't help as much as it does with gas engines. And small diesels still need to cope with higher pressures (the same higher pressures that make them more efficient), making them heavier than comparable gas engines, which is not good if you need every pound for your batteries.

For trains, weight is less of an issue and the benefits of having a purely electric drive-line (as supposed to a hybrid of electric and mechanical) are numerous. That's why most trains are diesel-electric or completely electric.

I wondered for some time why there aren't any diesel scooters, but I'm pretty sure now that the cost and weight issues are the reason. With your engine being part of the unsprung weight, using a diesel will have significant impact on the ride and handling.

pyramid 08-07-2011 04:13 PM

I think on diesel electric locomotives they don't have batteries. the energy from the generator goes directly to the motors.

joemama 08-07-2011 04:20 PM

A high revving rotary engine such as the Wankel would be much better suited to charging batteries. The only problem is that current rotary engines aren't very fuel efficient themselves..

Stereodude 08-07-2011 05:10 PM

Gas turbine to the generator would be even better. A properly designed gas turbine can run on almost any combustible fuel too.

[H]ard|On 08-07-2011 06:33 PM

[QUOTE=joemama;24834631]A high revving rotary engine such as the Wankel would be much better suited to charging batteries. The only problem is that current rotary engines aren't very fuel efficient themselves..[/QUOTE]

That's a terrible idea and you just said it yourself.

Lower RPM is always going to be more efficient than higher RPM, which is why diesels with long stroke and high torque are used in generators.

[H]ard|On 08-07-2011 06:34 PM

[QUOTE=Stereodude;24834709]Gas turbine to the generator would be even better. A properly designed gas turbine can run on almost any combustible fuel too.[/QUOTE]

Kind of like an Abrams tank. Or a cruise ship. They have large GE turbines and electric motors.

It's pretty dumb for a small car though. It's pretty dumb for a tank too imho, not to mention annoying for the poor crew.

Aldaris 08-07-2011 08:19 PM

I wouldn't discount the micro turbine just yet. I remember fooling around with this company's stock in a speculative play back in '08 (glad i got out when i did) [url]http://www.capstoneturbine.com/[/url]

Fiah 08-08-2011 02:32 AM

[QUOTE='[H]ard|On;24834846']Kind of like an Abrams tank.[/QUOTE]

Doesn't that thing guzzle down diesel like mad in comparison to its piston-engined peers?

TheMorlock 08-08-2011 02:52 AM

[QUOTE=Fiah;24835174]Doesn't that thing guzzle down diesel like mad in comparison to its piston-engined peers?[/QUOTE]

are there any other 55 mph top of the line tanks?

[H]ard|On 08-08-2011 03:22 AM

[QUOTE=TheMorlock;24835180]are there any other 55 mph top of the line tanks?[/QUOTE]

Top of the line meaning a heavy? And yes - shit tons, even shortly after the war and especially since the 60s.

Anyone who drives an abrams gets that WHEEEEEEEEEEEEEE as a permanent background noise in their ears :( Also due to the enourmous heat output of the turbine it's a magnet for heat seekers. :eek:

gribly 08-08-2011 11:00 AM

Ohh, an Abrams will do well over 55mph with the rev override flicked. Gotta watch the throttle, though, don't want to blow the tranny. Officially they'll do 60, because much more than that and you can break the tracks or cook the tranny.

I like Bradleys better, but that comes from being familiar with 'em.

Hardon, shut the fuck up. I ain't never seen no fuckin' Abrams powered by an electric motor, it's got an automatic in it!

Tex Arcana 08-08-2011 11:53 AM

[QUOTE=pyramid;24834626]I think on diesel electric locomotives they don't have batteries. the energy from the generator goes directly to the motors.[/QUOTE]

:nein: they have a combination of batteries and massive capacitors, the caps for huge push of power for start-up and acceleration, the batteries/generator for steady-state cruising. And they have regenerative braking.

[QUOTE=Stereodude;24834709]Gas turbine to the generator would be even better. A properly designed gas turbine can run on almost any combustible fuel too.[/QUOTE]

CitroŽn (?) did this in 1986-ish, a small gas turbine powering a generator straight to motors in each wheel. It was a concept, it was getting great mileage and decent performance, but it very quietly disappeared. Allnighte



[QUOTE=joemama;24834631]A high revving rotary engine such as the Wankel would be much better suited to charging batteries. The only problem is that current rotary engines aren't very fuel efficient themselves..[/QUOTE]

:wtf: you need to go back to your crack pipe and cocks, and stop posting in a serios intarweb foram. :tard:


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