the steamless steam engine

[Boston]

Ive been working on finding an alternative and preferably carbon neutral propulsion system

Stirling Powered Ships

the Erickson (sp?) built by John Erickson in the late 19'th century. Unfortunately a big portion of my Stirling engine library is out on loan right now so I can't give you the specifics. If memory serves, the engine was intended to put out 600 hp (447 kW) but only put out about 300 hp (223 kW). The pistons and cylinders were big enough and slow enough moving that a reporter got on them and rode up and down on the pistons.
More recently the French research sub Saga was powered by two 75 kW Stirling engines (200 hp total) and the Swedish military manufacturer Kockums installs two to four 75 kW Stirling engines (~100 hp each) in their submarines. These engines act as "top-off" auxillary engines allowing the submarines to stay stealthy on the bottom for weeks instead of days.

Philips also put a 75 hp (55 kW) Stirling engine in a small cabin cruiser. You can read about that project in "The Philips Stirling Engine" by Hargreaves. Unfortunately it's out of print.

-- Brent Van Arsdell, February 19, 2003

When the Ericsson was built...

I found the right book. The keel was laid in April 1852 and the ship was launched on September 15, 1853. There is a great account of this story and others in "Hot Air, Caloric and Stirling Engines" by Robert Sier. The ISBN # is 0 9526417 12. Published in Great Britain by: L.A. Mair, 20 Pines Road, Chelmsford, Essex CM1 2DL United Kingdom.

the sterling engine seems best suited to electrical generation
so one possibility is to go back to the electric engine powered rather than steam power system but replace batteries as a storage device

[PAR]

There are displacement engines in service, but they have several problems which makes them difficult to apply in the marine propulsion environment.

They would be great if you live in a geothermal active area, but have limited possibilities for us.

[Fanie]

Hi B,

The sterling engine is a very interesting case. It is the only engine that is >100% efficient.

A friend of mine built a couple of them, they're in his lounge. Placing your hand on a surface starts it turning, just the heat.

I think the problem on these is going to be the size of it to make enough power, and the heat exchange rate is limiting it.
Size isn't everything, you know

[marshmat]

Not sure what you mean by ">100% efficient", Fanie. The Stirling cycle can theoretically reach the Carnot limit (efficiency = 1 - Tcold/Thot ).

They make wonderful demonstation engines for the physics lab, and I've heard of them being used to power submarines. They're very quiet when running. There's a company called Whispergen that sells a combined heater/generator for boats and RVs based on a Stirling engine.

They tend to be rather large and heavy for their power output. Definitely feasible if you have a convenient concentrated heat source (perhaps a huge solar dish, or a little nuclear reactor?).

[Fanie]

Matt,

Please allow me to first compliment you on such a beautiful picture in the faces to names thread
http://www.boatdesign.net/forums/ope...tml#post271261

If you've got a nuclear source you can make very efficiently high power using steam. The old days of the big block of lead to shield the radio active source is in the past. They can produce a much smaller and as safe a container if not better than the lead. So the mono sailers get their way now too

The sterlings's handicap is their rather large and heavy for their limited power output. The biggest problem is probably the rate to heat and cool the gass. Engines require rapid movement to make effient work one can use, this seems to be the place where the sterling comes short.

I think my friend said they use a special gass that has the properties to heat and cool fast, hence it start turning from body heat already. but you're going to have a hard time getting some real power from it.

[marshmat]

Fanie,
May I ask what you've heard of as a replacement for lead shielding? I've spent a lot of time in the nuclear labs on campus in the last few years, and we'd love to have something better than lead.... toxic, expensive stuff that it its. But all the replacements we've found need to be much thicker, or else are tremendously expensive. The cancer centre uses ilmenite-blended concrete around their X-ray bunkers, and many nuclear plants do the same, but you need a lot of it- several metres thick in many cases.

You're dead right about the Stirling engine's weight problem. No matter how you swing it, you can't get a huge pressure rise or a high angular velocity in these things, and so they end up being bulky, heavy brutes if you want a large power output. Still, being extremely quiet and efficient, they do have their uses... that Whispergen thing, for example.

[Boston]

Im kinda in a hurry and there is a better video of this
but this is the basic form or the ford engine that ran on the stirling principal
it ran 170 hp and was designed as a car engine
they shelved the idea in the seventies



seems to me that power to weight may or may not work out advantageously I need some time to work out and present some equations
but there would be significant advantages of such a system if it could be made to work

steam engine boilers explode from time to time
these things do not
makes me kinda give em a second look

I say problems are made to be solved
so lets crunch some numbers and see what the possibilities are and arent
Im late to a suprise party so gotta go
but
Ill post the equations later tonight and will try to resolve them over the next few days
best
B

ps
if a girl named Fanie tells you size isnt everything
you might want to listen

[Boston]

hmmmmm
a suggestion was made on another page to look into Tesla turbines
turns out they are steam or compressed air bladeless turbines easily constructed and with high efficiency with low cost
might have to place them at the top of the consideration list as generator motors

although a more complex engine the Stirling needs no steam to operate on it is ridiculously priced from Whispergen
at about 20,000 for a 850 for the 800 watt model

dam disappointing to see some fools trying to take advantage of the green movement by overpricing there gadgets like that

although a representative of the company said the following in regards to the criticism as posed by another

William S ********, I am afraid is showing some ignorance here due to his obviously steadfast grip on traditional generating technology. The DC (12 or 24V- not AC take note Mr Scott) WhisperGen is part of a heat and power system designed for marine leisure craft in the 30'to 60' size (monohull) It uses the DC "buffer" concept whereupon the main battery bank becomes the energy source for all electrical loads, AC and DC, and the WhisperGen replenishes the batteries when their capacity falls to a preset value. Its 70 Amp @ 12V output is more than enough to accomplish this. The only difference is the time taken in charging as against a loud, smelly AC genset with charger. We have around 400-500 units all over the world supplying all the energy needs for yachts of cruising size. A ample supply of piping hot water delivered while the unit is operating is an added and much appreciated advantage. AC gensets work on a peak power output while the WhisperGen works on a daily average. As far as economics are concerned, the unit is over 90% fuel efficient, around 0.7Lt of diesel per hr. The minimal maintenance required (5oo hour checkover as against oil and filter,etc every 50hrs makes the system decidely economic over a 2-3 year time frame. Do your homework before bad mouthing a superb piece of engineering Mr *********!

[PAR]

They're not taking advantage (Wispergen). These systems were well above the more conventional systems long before it was "stylish" or profitable to be green.

[Boston]

for $20,000 it had better dress nice and take me out to dinner

after looking at the tesla turbines I think it might be more advantageous to consider the Stirling generator first
it could easily be DIY and could use the same gen system as the vawt turbines first mentioned in one of the other threads
that would keep the boiler out of the picture completely and keep the electrical components standardized throughout the vessel
ist more complex to build than the T turbine but it eliminates the need for a boiler and it runs at slower rpm's which means less were and tear on associated components

[rasorinc]

Bos, why don't you write Ford about their engine requesting the engineering material and data and tell them what your trying to do.(convert it for Marine use)
Offer them a contract giving them some % if you are able to make a usuable end product. Ask for an engine. They have no use for them and if they might make a buck in the future, Why not? Just a Thought. PS be sure to build your frames out of Black Locust. Stan

[Fanie]

Matt, I don't know any specifics, all I know is what one of the guys here told me confidentially that was involved in the nuclear source development, and that was some years ago already. The philamons are scared they are going to be sterilized (another white plot) so as far as I know there is no one doing any development here any more. SA was the leaders in nuclear development at some stage. Now I don't even know if the place still exist. All capable whites get kicked out of their jobs and replaced.

Nuclear engines will be very economic to run. It's going to be one of the sustaiable energy sources of the future.

[Fanie]

Did someone say Ford ? I thought those old boat anchors were banned long ago

[rasorinc]

What I know is that the US took everything including studies, engineering and the rest was destroyed so nothing relating to Nuclear was left. Sort of like it was never there.
Fanie, FORD stands for Figure On Repairs Daily

[Fanie]

I thought it was First On the Rubbish Dump, then some smart ass came up with the argument that it was because it towed the Chevy there.
Needless to say we're not friends any more

You guys have nuclear driven ships. One of your war ships was here in SA a while back and that was nuclear driven. So was the russian sub the was here just prior to that. Probably a good thing they didn't get here at the same time... phew