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Posted
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samzenpus
on Thursday July 16, @06:57AM
from the batteries-not-included dept.
coondoggie writes
"Some might call it an enormous floating Prius, but others will call it a step in the right direction: A new hybrid electric engine for US Navy ships that promises to save up to 12,000 barrels of oil a year per ship.
The folks who brought you the Predator unmanned flying aircraft, General Atomics, this week got $32.7 million to develop a proof-of-concept Hybrid Electric Drive (HED) system for a full-scale demonstration on board the Navy's DDG 51 Class destroyers.
DDG 51 destroyers are powered by General Electric gas turbines capable of moving the ships along at over 30 knots or about 35 mph. The General Atomics system would meld into this system and let the ship use electric power for slow-speed maneuvers. The engines would provide more power as the ship needed to go faster."
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Nice thing. (Score:2, Funny)
Now the US navy can bring death upon the infidels in a clean and environmentally safe way.
Re:Nice thing. (Score:5, Interesting)
Parent
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Re:Nice thing. (Score:5, Informative)
Parent
Re:Nice thing. (Score:5, Informative)
Yes, you hear propellers below cavitation speed. Thirty tons of brass doesn't move hundreds of tons of water "quietly". Another sonar operator can hear it from miles away. Standing in after steering, the propellers are quite loud all the time, and very loud any time they make a change in speed. I spent many an hour standing watch in that smelly little room. (and after all that time, I never figured out why it was always so freaking SMELLY!)
So far, I've not seen anyone mention one of the biggest benefits of electric power. Torque. When you flip the switch and/or turn the rheostat, you have power NOW! Gas and diesel are quite slow to build up torque, even in the turbine engines that the Navy uses. Boilers are somewhat better - depending on whether you've already built up a head of steam or not. If not, you're still dependent on turbines spinning up to bring oxygen to the fire. With electrons, there is no perceptible delay.
The result? Sonar hears a torpedo coming in, the port screw is put into full reverse, starboard screw is full forward, and the ship spins (not turns, but spins in place) in about a minute, instead of 4, 5, or 6 minutes.
Alright, today's enemies aren't likely to have torpedos, but the maneuverability can be just as valuable in many other situations - including entering and leaving port when some idiot on a ski boat ignores the rules of the road.
Parent
Re:Nice thing. (Score:5, Informative)
Except that a lot of the sound comes from the propellers alone.
Not in the way you think. The propellers are the point of contact with the sound transmission media - water. The propeller connects with the drive shaft and transmission. The transmission connects with either an electric motor or an engine. And in some cases, multiple engines and/or motors. The vibration and and engine noise is then transmitted through the transmission, the drive shaft, and then propeller, where it is then transmitted into the water for all to hear. This is the primary reason many military vehicles have been heading toward an electric drive system where the ICE is used to turn a generator rather than directly drive the propeller. This is also the reason modern diesel subs have been getting so quite.
In short, the propeller on modern military ships make the vast majority of their noise because they are a transmission point for everything mechanical attached to it, not because its spinning in the water. Which means, using electric motors to spin your propeller, especially at slow speeds can make you incredibly stealthy despite the fact a propeller is still spinning in the water.
Parent
Re:Nice thing. (Score:5, Informative)
in this particular case, the Daring class destroyers also use a combined gas and steam turbine to generate the electric power required for propulsion, thereby improving fuel efficiency.
the interest in electric propulsion is mostly due to other factors, tough: lower heat/sound signature, higher efficiency at slow speed etc.
Parent
Re:Nice thing. (Score:4, Funny)
My destroyer is like VRRRRRNNN.. VRRRNNNN... VRRRRRRNNNNNN! What does your destroyer sound like?
shhhhhhhhhh
That's cool.
Parent
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What would happen... (Score:4, Interesting)
If 30 tons of Lithium batteries burst open on the high seas? After,say, a torpedo strike?
I bet it would be spectacular.
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we ca ask the electrical/diesel submarines .... not new tech at all
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the ship use electric power for slow-speed maneuvers
But I think this may be a hybrid like a train.
Re:What would happen... (Score:4, Informative)
If you check out the Journal article [wiley.com], they describe this system as an electric motor mounted on the drive shaft, powered by existing auxiliary electrical generation capacity on the ship. The motor would only be used at speeds under 12kt at maybe 1/10th peak power output, when the efficiency drops off considerably and the turbines are basically idling. The system would be set up to run in reverse, providing power back to the ship, presumably for future electric artillery that the Navy is developing.
Parent
Re: (Score:3, Informative)
I thought the new destroyers were also nuclear.
DDG-51 destroyers are Arleigh Burke class. There's 55 of them so far; none are nuclear powered.
Rep. Gene Taylor made some noise about canceling the Zumwalt/DDG-1000 class (gas turbine-powered) in favor of a nuclear Burke variant, but it hasn't happened.
Wasn't there a big show of the all nuclear carrier group that could go around the world with having to refuel?
What you are referring to is 1964's Operation Sea Orbit [wikipedia.org]. You need more than a carrier and two missile cruisers to make up a carrier strike group. Nuclear-powered destroyers and supply ships were not built, and the all-nuclear Navy never materialized.
Since the
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Probably similar to what happens when one of the Soviet-era sodium-cooled nuclear submarine gets hit... really a torpedo hit that breaches the hull is going to be a Bad Day no matter what.
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Lithium batteries currently in production aren't rechargeable, so I doubt they would use them. Lithium-ion batteries don't contain metallic lithium (unless they are malfunctioning), so breaching them shouldn't be particularly interesting.
Re:What would happen... (Score:4, Funny)
Well, if it *is* to be the Prius of the high seas, let's hope they at least make it a decent looking ship. Not something fugly like the Prius on land is...
Also, it will need Obama '08 and "Coexist" bumper stickers.
Parent
Not exactly a new idea (Score:2, Interesting)
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use the motion of water past the hull and in the wake to generate electricity while the vessel is underway.
Ummm.....no I don't think so. Far better just to keep some of the power generated by the turbines.
Re:Not exactly a new idea (Score:5, Funny)
Parent
Sails are no laughing matter! (Score:3, Informative)
http://www.google.com/search?hl=en&q=sky+sail&aq=f&oq=&aqi=g10 [google.com]
Cheers.
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German U-Boats in in WWII had dual diesel/electric engines.
Essentially all submarines in WWII had dual diesel/electric engines, and basically any non-nuclear submarines today do, as well. Earlier than WWII, the electric side was standard on all but the earliest impractical prototypes, and the other propulsion was experimented with until everyone settled on using diesel train locomotive engines.
That wasn't for efficiency, but because they couldn't use the fuel-burning engines underwater.
Submarines (Score:5, Interesting)
I would have thought that the Navy would have led hybrid engine research with everything that was done in WWI and WWII for submarines. Essentially those were hybrid engines, with the diesel's powering the boat on the surface and recharging the batteries, and then using the batteries when the ship was submerged.
That has all been supplanted by nuclear submarines, but you have to wonder where battery technology would be today if the Navy had kept using that system.
Re:Submarines (Score:5, Informative)
Um, the Navy sort of does. Every nuclear submarine out there has a big diesel engine and an array of batteries on it. They are for use when the big tea kettle is down for maintenance and/or emergency situations.
Parent
Re: (Score:3, Interesting)
While the US knowhow in that area, it hasn't disappeared in other parts of the world, for example Sweden and Germany. Sweden was also the first to use a Stirling engine, so it can recharge the batteries without having to go to snorkle depth.
Only? (Score:5, Interesting)
technical and fiunancial details. (Score:4, Interesting)
http://www.informationdissemination.net/2009/07/good-reason-for-flight-iii-burkes.html and the reasons for this work.
A defence Industry view
http://www.defenseindustrydaily.com/327M-to-General-Atomics-for-DDG-51-Propulsion-System-Prototype-05598/#more-5598
A general Atomics view
http://www.ga.com/news.php?read=1&id=262
Too bad we don't have this already (Score:3, Insightful)
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Where are these nuclear wessels?
Re:Too bad we don't have this already (Score:4, Informative)
Parent
Regenerative Braking (Score:4, Funny)
How does regenerative braking work in the high seas?
different type of hybrid (Score:4, Informative)
What the Navy means by 'hybrid' is not exactly what you'd expect. TFA is light on details, but I suspect the idea is to use the electrical generators on the ship for low-speed propulsion, instead of having to run the main gas turbine engines at 10% load, at which they're very inefficient. There'll be no batteries involved, and no regenerative braking.
Many warships already have two plants capable of driving the propellers. Not so much the USN, but European navies often use gas turbines to provide high speeds (30+ knots), plus a set of diesels for lower speeds (up to 20 kt).
For new ships, electrical propulsion is being looked into for the same reason: you can switch generators on and off so you always have them running at their most efficient power setting.
What about nuclear batteries? (Score:3, Insightful)
The REAL reason for electric boats (Score:4, Insightful)
Can you say "Rail Gun" or "LASER"?
These new weapons technologies (needed for interception of ballistic or hypersonic projectiles) will require a colossal amount of electric power. If the ship is already geared up to be capable of storing a lot of power in its batteries, a major hurdle in the deployment of these weapons are overcome.
Maybe they could even use the tremendous kinetic energy of the ship moving at high speed to generate electricity from the motors. Probably only useful in an emergency because it makes your ship a sitting duck!
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Re:So that's where our tax dollars go. (Score:5, Informative)
Parent
Re:So that's where our tax dollars go. (Score:4, Interesting)
> Also oil costs dont factor into the
> cost of physically refueling the ship.
Well said. That includes the time it takes to complete the evolution. Especially underway it's a major pain; running those hoses over and keeping station is no joke. If you could cut the number of UNREPs in half you'd be saving resources all over.
Parent
Re:So that's where our tax dollars go. (Score:5, Insightful)
Parent
Re:So that's where our tax dollars go. (Score:5, Informative)
Parent
Also, strategically (Score:4, Informative)
It is also an important strategic advantage to have a ship that is more fuel efficient as it can stay in the arena for longer before it needs to be refuelled.
This is likely a main driver for this research.
Parent
Re:So that's where our tax dollars go. (Score:4, Insightful)
$100 per barrel= costs at the refinery.
The ships are generally in nasty, remote locations. Factor in the cost of building a supply ship and fueling that ship to get the fuel to the destroyer, PLUS escort, PLUS lost mission time and extra miles to go to refueling, and you will probably break even in the first year.
And then the ship has 30 more years to go.
I guess your tax dollars didn't go to elementary math & common sense education, aka high school :-)
Parent
Re: (Score:3, Funny)
Well, the primary benefit is that we can call this a Class 1 Naval Drive, thus affirming our fantasies about one day living like Commander Jameson.
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Lower fuel consumption would (slightly) increase the ability to oper
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You forgot to mention that the Navy has a stated interest in rail guns and energy based weapons. They're already building excess generating capacity into their designs to eventually accomodate those if/when they're ready for deployment, so they might as well take advantage of it while waiting.
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Seriously, just because the general principle has been in use somewhere else, doesn't mean you can't improve on it - and scaling something up is not necessarily a trivial matter.
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Turbo-electric drives were standard for US battleships of the WWI period, because of fuel economy. The USN wanted to operate at very long ranges from its bases. This continued with the battlecruiser designs, of which two were converted to aircraft carriers. One of those carriers once powered a city (Tacoma, I think) during a power failure.
The Washington Naval Treaty of 1922 ended this, since it defined a new "standard displacement" (method of calculating a ship's weight) that didn't include fuel, so t