What is the Latest Technology for Diesel to Electric Conversions?

[kach22i]

Diesel to electric conversion

1. What is the "lightest" and most practical (affordable) set-up TODAY that one may convert Bio-Diesel fuel to electricity for use in electric motors?

2. What disruptive technology is just around the corner (near future, 5 years away) which one may convert Bio-Diesel fuel to electricity for use in electric motors?

The context: Automotive, Naval, Aircraft and landbased systems.

The "lightest" comes into being a technology which is transferable to all types listed.

Macro, micro and everything in between may be included, but my mindset is in transportation.

What's out there?

Are fuel cells only for hydrogen?

 

[mgb_phys]

1. What is the "lightest" and most practical (affordable) set-up TODAY that one may convert Bio-Diesel fuel to electricity for use in electric motors?

The engine in your Volkswagon + a dynamo.
A diesel engine will burn pretty much anything liquid that can burn. It doesn't really matter if it waste oil from french fries, biofuel or dead dinosaurs.

2. What disruptive technology is just around the corner (near future, 5 years away) which one may convert Bio-Diesel fuel to electricity for use in electric motors?

Huge government grants to farmers to grow bio fuels, to replace the huge government grants to grow corn syrup.

Are fuel cells only for hydrogen?

Most fuel cells combine hydrogen and oxygen. This is reasonably energy efficient and has the advantage that the waste product is water.

 

[Danger]

I suspect that it depends upon the scale. A gas turbine is probably the overall best, but a 2-stroke Diesel would be more practical for a small application. Just my best guess, though.

edit: Hi, Mgb... you sneaked in while I wasn't looking. Isn't a 2-stroke lighter for the power produced?

 

[mgb_phys]

I've only seen 2stroke diesels on really massive (marine or railway) engines.
I suppose this is because you need a turbo to get the compression and it wouldn't be worth making a two-stroke diesel chainsaw with a turbo (might be fun!)

In a big 2-stroke diesel is as close to thermodynamically perfect as you are going to get. That (and maintenance simplicity) is why most ships use direct diesel engines instead of turbines.
I imagine cars aren't two-stroke diesel because of noise or vibration.

 

[kach22i]

In a big 2-stroke diesel is as close to thermodynamically perfect as you are going to get. That (and maintenance simplicity) is why most ships use direct diesel engines instead of turbines..

I've read that 2/3rds of all new naval (non-rec) designs are Diesel to electric. It started with tug boats so that they have instant start up and torque (no problems matching drivetrain and engine output to load). Now used in cruise ships (turbine) to help lower vibrations and to help move it's large mass around using stearing pods.

There is a large 100 long hovercraft being built which will be using Diesel to electric converter. I'm thinking on a scale at least half of that for widest application in real world.

 

[mgb_phys]

Cruise ships, tugs and specialist rig support boats are diesel-electric with steerable thruster pods. This makes the ships highly manouvarable and in the case of cruise ships has the advantage of reducing noise and vibration and saving a large amount of space that the propeller shafts wasted. My company makes the laser rader system that controls the docking!
Cruise ships also use a huge amount of electrical power for the passengers so they sometimes have separate gas turbines as auxillary generators. These are often the same engines as used on airliners.

Big cargo ships use direct drive 2 stroke diesel as it is the most fuel/cost efficent. These engines get close to the theoretical thermodynamic efficency.
Fast warships use gas turbines as they give the most power to weight if fuel and maintenance costs aren't an issue.

 

[kach22i]

Let me add that the US military is moving toward Diesel to electric conversion systems as they already must generate a lot of electric power to run their computers, communications, weapons and logistic hardware.

If you can build a better mouse trap, maybe uncle Sam will fund it.

The DoD SBIR & STTR Programs
http://www.acq.osd.mil/osbp/sbir/

 

[mgb_phys]

Let me add that the US military is moving toward Diesel to electric conversion systems as they already must generate a lot of electric power to run their computers, communications, weapons and logistic hardware.

They also like steam turbines because they use a lot of high pressure steam to launch aircraft.
For very big ships (aircraft carriers) you use steam turbines.
For big/slow you use direct diesel
For big and fast you use direct drive gas turbines.
For manouverable or quiet you use electric thrusters, generated from diesel or gas turbine. Since marine dielsels and gas turbine will run on pretty much anything flammmable they could probably have both on the same fuel.

One other possible advantage of thrusters for warships is that each thruster is independantly powered and steered and the connection to the engine is just an electrical cable so it would be much easier to have multiple redundant systems.
A single prop shaft and rudder is very vunerable to a single lucky hit - as the Bismark discovered!

 

[kach22i]

They also like steam turbines because they use a lot of high pressure steam to launch aircraft.

Article is from 2001, I've read that they have already installed a few of the electric (electromagnetic) catapuls.

Navy to Phase Out Steam Catapults on Carriers
http://www.nationaldefensemagazine.org/issues/2001/Jul/Navy_to_Phase.htm
Steam and hydraulics generally are considered a “maintenance nightmare” on board Navy ships, particularly aircraft carriers.

 

[mgb_phys]

Article is from 2001, I've read that they have already installed a few of the electric (electromagnetic) catapuls.

We had a grad student who was a navigator on carriers, I asked him why they still used steam catapults instead of something more modern.
Basically they like simple heavy reliable systems. The carriers were designed to still operate when the entire battle fleet had been hit with multiple H-bombs, so anything that you couldn't repair in the middle of the atlantic with a sledgehammer and a file was out of the question.
I guess now that is less of a threat - they, like everyone else, want new expensive complicated toys to play with.
It would be interesting to know what the interference from a 100m long electromagnet capable of throwing a 30ton aircraft at 150mph does to all the other electronics around it!

 

[russ_watters]

Most of the "normal" warships in the navy (frigates, destroyers, cruisers) use direct-drive GTEs with variable pitch props. The frigates use diesel generators for power and the destroyers and cruisers use GTEs.

GTEs seem to be on the verge of replacing diesels when it comes to small-scale power generation, cogen, etc. for buildings and industry.

 

[russ_watters]

It would be interesting to know what the interference from a 100m long electromagnet capable of throwing a 30ton aircraft at 150mph does to all the other electronics around it!

Degaussing already kills computer monitors and tvs on navy ships pretty quickly.

 

[mgb_phys]

GTEs seem to be on the verge of replacing diesels when it comes to small-scale power generation, cogen, etc. for buildings and industry.

Hard to beat for low maintenance long service life - especially the large installations that just use slightly modified aircraft engines. As I said in the other thread https://www.physicsforums.com/showthread.php?t=182038 the main modification for a RR Trent is to make sure it is VERY securely bolted down.
I think some of the cruise ships actually use this engine for aux power and diesels for the electrical propulsion generation.

ps They still degauss the hulls for protection from magnetic mines? I would have thought that with sensitive solid state magnetometers you could detect a ship how ever well it was degaused. The devices we use have to be tested/calibrated in the middle of a field in a wooden shed with copper nails.

 

[kach22i]

GTEs seem to be on the verge of replacing diesels when it comes to small-scale power generation, cogen, etc. for buildings and industry.

1. What is a GTE?

2. Does it use steam?

 

[russ_watters]

Gas Turbine Engine. AKA a jet engine. The engine the Navy uses (GE LM2500) is from the same family as what powers the DC-10.

 

[Astronuc]

I've only seen 2stroke diesels on really massive (marine or railway) engines.

Back in the old days -

ALCO and EMD (subsidiary of GM) were the major suppliers of diesel locomotives. GE became the third major supplier, and supplied ALCO with motors and generators, until ALCO went out of business.

Anyway EMD favored 2-stroke, while ALCO and GE favored 4-stroke. ALCO and GE units 'smoked' a lot.

http://www.sdrm.org/roster/diesel/alco/index.html - 244 and 251's were standard
http://alcoworld.railfan.net/alco_eng.htm - IIRC, the 244 came out in 1944 and the 251 in 1951.

http://www.sdrm.org/roster/diesel/emd/index.html - 567 was standard until replaced by 645, then the 710.

Fairbanks Morse was another supplier of railroad diesels, but gave up early. They concentrated on marine diesels.
http://www.fairbanksmorse.com/marine_power.php

Detroit Diesel favored 2-stroke and Cummins 4-stroke.

Cat got into the RR diesel engine late - as replacement power. IIRC, they used 4-stroke for large diesels.

 

[AlephZero]

Gas Turbine Engine. AKA a jet engine. The engine the Navy uses (GE LM2500) is from the same family as what powers the DC-10.

And various R-R marine gas turbines as well.

"AG9140 generator sets power all US Navy DDG51 destroyers ... The MT30 has been selected to power the engineering development model for the US Navy's DD(X) future surface combatant, [and] the Lockheed Martin Littoral Combat Ship ..."

http://www.rolls-royce.com/marine/downloads/market/naval_range.pdf

The MT30 is a marine version of the Trent.

It's a bit ironic that the USN are happy with non-US, engines but they won't let UK engineers on the ships to install them because we are "aliens". Did somebody just say "special relationship"?

 

[kach22i]

I'm having a hard time thinking of thirsty gas turbines engines as efficient for anything. Light weight and powerful, yes. However you have to lug all the fuel around and fuel costs money.

These 40,000 hp applications are out of scale with my nomal frame of reference (automobile engines). What hybrid system would be best for something 1/10 as powerful and which may not be operating 24 hours a day seven days a week?

 

[mgb_phys]

These 40,000 hp applications are out of scale with my nomal frame of reference (automobile engines). What hybrid system would be best for something 1/10 as powerful and which may not be operating 24 hours a day seven days a week?

4000Hp is still pretty large (railway locomotive or small ship) for that you would use a two stroke turbo diesel. For auto applications 40-200Hp a small automotive turbo diesel.

 

[kach22i]

4000Hp is still pretty large (railway locomotive or small ship) for that you would use a two stroke turbo diesel. For auto applications 40-200Hp a small automotive turbo diesel.

Thank you, this is more or less what I first thought, just wanted some new ideas to kick around and consider.

 

[brewnog]

4000 horsepower for electric power generation is in the realms of a turbocharged, charge cooled Diesel reciprocating engine. 4000hp is around the boundary between 2 and 4 stroke, with 2 strokes taking anything much larger (because more clever fuel systems can be used, and the engines run at lower speeds).

 

[russ_watters]

I'm having a hard time thinking of thirsty gas turbines engines as efficient for anything. Light weight and powerful, yes. However you have to lug all the fuel around and fuel costs money.

Generally bigger is more efficient than smaller, but anyway, if you want small, here are 30kW turbine generators: (about 45 hp with a little efficiency loss)

http://www.microturbine.com/prodsol/products/index.asp

 

[kach22i]

FYI, on the PBS TV program "Autoline Detroit" this weekend Bob Lutz of GM talked about the Chevy Volt. It's powertrain is pretty what I have been asking about and looking for. Its a classic disruptive technology although Lutz is quick to point out there are no conceptual hurdles to overcome (without whispering the word "Hydrogen"), it's pretty much using technology that's already out there - just making it better.

Watch the interview here (The Shock of the New):
http://www.autolinedetroit.tv/show/1133

Link to the "Volt":
http://www.chevrolet.com/electriccar/

Introducing a new kind of electric vehicle — Concept Chevy Volt. It’s unlike any previous EV (electric vehicle), thanks to its innovative rechargeable electric drive system and range-extending power source. It can be configured to run on electricity, gasoline, E85 or biodiesel. So you have at least a couple of options for the most efficient drive — all made possible by GM’s innovative E-Flex Propulsion System.