Cheap Fuel?

[FAST FRED]

Contemplating the state of the diesel prices got me thinking,

A modern diesel with a big computer will vary the injection and fire 3 or 4 times with each power stroke , vary the valve timing as the rpm changes , and can eat fuels of different cetane numbers.

When we purchase fuel we are purchasing a WEIGHT of usefull energy , although its usaually marketed in gallons.

COAL is only $30 a ton or so , depending on quality and where in the world you are.

So is it time for coal fired steam to come back to small (35 to 75 ft) boats?

I have seen steam home heating gear from the early 1900's that was painless , the owner only requiring one shake down and stoking per day , yet each room was its own Zone in terms of temperature , all with out Electric.

So with nice electric black box the fuel , feed water , pressures , volumes and temp of the power plant and various consumers could easily be automatically controlled.

AS steam has huge torque at very low RPM a huge (read efficent) slow turning prop and central heat would be avilable to the cruiser.

I realize in Euroland the endless burocracys would probably nix the steam boiler idea (as they do most usefull advances) but in the free parts of the world it might be fine .

Purchasing what is "out of favor" at the moment is frequently cheaper than going with Off The Shelf.

Comments , Ideas?

FAST FRED

[Wellydeckhand]

I vote coal.................. But too many people think of pollution.

[StianM]

This is a simple steam arangement just out off my head with higpreshure and low preshure turbine and a generator turbine.
If annyone decide to go for steam don't use coal, but oil.
Go to a car dealer or a dock/shipyard and they are happy do giwe you old engine oil,gear oil or hydraulic oil that they normaly have to pay to get deposed.

http://www.aalborg-industries.com/if...oductrange.jsp
http://www.gepower.com/prod_serv/pro...s/en/index.htm

Some disadvantages with coal is the volume to weight ratio and another is it's energy. You will nead 54% more weight off coal to get the same energy as the diesel would require. And then you have loss in boiler, loss in pipes and steam engine and alot off energy go to the ocean for cooling purposes to condence the steam to water for reuse.
With a smal amature system you might have to use 4tonn of coal for 1tonn off diesel. All that coal is going to make the weet surface off the ship increase and so will the heavy steam macinery and you will have increased drag. And the coal will take up alot off space you actualy want to use for other things like beer.
Use spil oil if you really want to go for steam.

Where ever you live in the worl some pulution act will catch up with you sooner or later that put a end to coal use.

[dimitarp]

You can gasificate the coal preliminarily nad the to use the gas in diesel

[StianM]

Originally Posted by dimitarp

You can gasificate the coal preliminarily nad the to use the gas in diesel

That could be done. I ben thinking a litle about it myself, but I'm unshure about the volume/kg off coal. How mutch space dos it nead?

Like the way you think man

[yipster]

like the way you guy's think also
high and low pressure steam turbines,
old oil can even feed the primairy gas turbine

[Thunderhead19]

A correctly designed combution process can minimise pollution . Coal is not really such evil stuff you know. Heck, buring garbage can be usefull too.

[StianM]

Yes a gasturbine is something I could like.
Only problem in a marine inviroment are salt in the air that could get stuck on the blades making it less efficiant and it's less efficiant than a diesel.
It would be convineint, you could burn about annything.
Propan, butan, gasificated stuff, diesel, alcohol and oils with no major changes.

I can't really see that a correctly designed combution process can minimise pollution since this is something they are working with in huge coal powerplants and is not a sience that myself could do with anny luck.

Did annyone calculate how big increase you would have in wetted surface bacause off heavy steam macinery?

[Greenseas2]

In aircraft a small turbine has been developed and is now sold for turboprop powering experimental aircraft. Also, before steam engines were phased out of large ships, they had replaced piston type steam engines with turbines. This may be a possibility for using steam to drive small private vessels. I have no idea what the best fuel might be. Just thoughts

[StianM]

Originally Posted by Greenseas2

In aircraft a small turbine has been developed and is now sold for turboprop powering experimental aircraft. Also, before steam engines were phased out of large ships, they had replaced piston type steam engines with turbines. This may be a possibility for using steam to drive small private vessels. I have no idea what the best fuel might be. Just thoughts

Steam turbines was developed because they could develop more power and take less space then a steam piston engine.
They was in use mainly where diesel engines was not powerfull enough, but today steam turbines are replaced by diesels because they now make diesels that are close to 100 000kW.

The use off steam turbines today is limited to nuclear power and old instalations + that some ships use exhaust heat to produce stream for electric production.

Where did you see that aircraft turbine???
Would like to do some study on it

[moTthediesel]

You can gasificate the coal preliminarily nad the to use the gas in diesel

Get a copy of Weston Farmers "From My Old Boatshop" (everybody should have that great book anyway). Old Westy was a great fan of "Producer Gas" systems, and he talks about them in some detail.

moT

[FAST FRED]

Most steam engines were HUGE as Large power was required to go fast..

With only about 100 hp MAX required (probably 50 because of the steam engines torque curve) the engine , a 3 cylinder should weigh no more than a similar motorcycle engine. Steam engines was made long ago with out Titanium and Un-obtanium , just machined iron , or steel when avilable.
And nothing is highly loaded or fast moving.

So no need for turbines or other big buck items.

Sure waste oil could be a substitute (or at least used for starting the coal) but I worry that cruising it may be hard to get a tank trailer and get a refill at low cost.(some local will be in that business already).

"You will nead 54% more weight off coal to get the same energy as the diesel would require. And then you have loss in boiler, loss in pipes and steam engine and alot off energy go to the ocean for cooling purposes to condence the steam to water for reuse.


The excess heat could be used for intereior heat or perhaps into air cond or refrigeration using an ammonia cycle coolant system, that WORKS with heat.The excess heat can also be used to distill water , saving $5000 worth of Reverse Osmosis gear + its huge mainanace.

If the fuel use can be matched to the power requirement an economical vessel should result as many displacement boats will cruise on only 20 or 40 hp.(1 or 2 GPH of diesel).

Can we get 40 hp for an hour from 16 lbs of coal?

FAST FRED

[yipster]

[Greenseas2]

Fred, Some time ago Popular Mechanics magazine had an article on converting larger air compressors in to steam engines. The compressors were about the same size as a large motorcycle engine. The use for the steam engines was to turn electic motors for home elcetricity production. The boiler was not overly large and made from a used propane tank. As far as fuel goes to produce steam, we're back to used vegetable oil collected from restaurants and bakeries that only needs to be filtered, not refined. Without the refining process, screening and filtering would produce fuel for the burner at about ten cents a gallon. A little innovation goes a long way.

[StianM]

If you nead 100hp diesel you would nead the same in steam.