the steamless steam engine

[sigurd]

Landlubber, heat output from a heat engine is directly inversely proportional to its efficiency. Energy in is energy out, so by and large and simplified, if it is not mechanical, it is thermal, whether that is due to friction or hot exhaust or cooling water/air. So if the IC is more efficient than the stirling, then what you say is true.
However closed systems such as stirling and all efficient steam engines, needs cooling of the medium, unlike the IC, which rejects most of the heat through exhaust. That can be a problem for the formers, in hot climate. Bigger or more power consuming cooling systems may be needed. On a boat however, this should be not a problem, since cold water is always available.

[sigurd]

Originally Posted by apex1

First point is, that you MUST get rid of ALL traces of lubricant, you otherwise destroy the boiler / piping in short time.
Next is, that gravity systems and mechanical filters let the condensate cool down quite much, due to the great surfaces and time of process required.
THAT is the high energy loss in general.

And it is not only carbon residue, the lubricants build up acids.
[b]

Peter Brow is designing a steam car. Here is what he wrote over at steamautomobile.com phorum. I bolded some text.

The 6 main oil/water separation methods I have read about being tried in steam cars are gravity separation, centrifuge, boiling, exhaust separators, coalescing filters, and oil absorbents. They can be used in combination, in different parts of the powerplant.

Gravity separation is putting (nondetergent) oil and water mix in a tank or chamber, and letting the oil float to the top, where it can be skimmed or overflowed off. There are off-the-shelf belt, disk, and tube skimmers, which run an oil-grabbing moving element (often acrylic) through the oil layer, then scraping the oil off the element continuously. Skimmers like this are used in machine shops to separate cutting lube from cooling water, and in other processes. Compact, and negligible electric/hp use.

The Delling car had an interesting and extremely simple gravity separation device. It was simply a small chamber, into which the oily water drained from the condenser. The bottom of this chamber was plumbed to the bottom of the water tank, so oil was trapped in the chamber and did not go to the main water tank.

The centrifuge was used successfully in Peter Barrett's steam car, and I believe in the Carter car also. In the Barrett system, both crankcase oil and condensate from the condenser went to a common inlet to a compact centrifuge (based on a Swedish cream separator), which sent pure water back to water tank, and pure oil back to crankcase. Extremely effective. Tested blueprints for the Barrett centrifuge are available. Requires negligible horsepower to operate; Barrett ran his from the main engine via a tiny (O-ring) round belt.

Heat-separation has been used in some single-acting steam engine crankcases, including as I recall the Besler cars. Just a loop of the exhaust steam line in the oil pan, keeping the crankcase too hot for water (condensed steam blow-by from piston rings) to accumulate. The water vapor boiled out of the oil can be condensed and recycled. In my shop experiments, I found that even detergent oil can be heat-separated, if heated to about 350 degrees Fahrenheit. Detergent oil foams up like crazy in the process, so leave several times the oil/water volume in the tank. Nondetergent oil/water mixes foam less while heating. I plan to use an oil tank, with a heat jacket connected to the boiler exhaust gas flue, to boil water out of recycled (nondetergent) cylinder oil.

Exhaust separators are commercially available. These go in the exhaust steam line, and give spin or turbulence to the exhaust steam to throw oil droplets in exhaust steam out of suspension. They catch the oil, and usually some condensate, and remove these from the exhaust steam. Some need manual draining; others have a float valve to drain themselves. Makers claim 99%-plus efficiency for commercial units, but I have been told that with some types of separators this is only at high flow rates. In a steam car, the exhaust steam is usually moving at a fraction of its maximum rate. Exhaust separators come in several types, some with baffles, some with cyclone chambers, some with axial-flow "spin fins" and liquid collector rings. Many have been used on steam cars, with varying degrees of success reported.

Coalescing filters have been experimented with. This is a filter unit that you pump an oil/water mix through, and the oil blobs together and floats to the top of the outlet chamber. Water separates to the bottom of the chamber.

Oil absorbers are off the shelf, dirt-cheap, and very effective. Reportedly these are being used in a number of steam cars. McMaster and some other suppliers sell good off-the-shelf absorbers in various shapes and sizes. A mass of hollow-fiber polyethylene fluff is stuffed into a bag, which you drop in a tank. The bag floats at water surface, soaks up oil like crazy, and holds it. The oil is drawn into and held in the hollow fibers by capillary action. Absorber holds huge amounts of oil, and is discarded when full. This could be viewed as analogous to the oil filter in a gas car, but longer-lasting. The McMaster cat listing tells the oil capacity of the absorbent filters they carry.

I am probably overlooking one or more other oil/water separation methods. With nondetergent oil, it is possible to get complete separation of oil and water with one or more of the above methods. With the liquid centrifuge, hermetically pure oil and water can be achieved.

There is also a school of thought that small amounts of oil in practical steam/water systems provide valuable protection against corrosion and scale/deposit buildup, while allowing use of less expensive and more easily-worked materials and simpler/cheaper equipment. IE, perfect oil/water separation, or oil-free operation, is not necessarily the best way to go.

In the current SACA Bulletin (January/February 2010, volume 24, #1, p. 19), SES engineer Stan Jakuba states that in the circa-1975 SES steam car "the condenser effectiveness was not impaired by any of the [nondetergent, non-compounded] oils tried ... Nor did the [ultralight/high-performance monotube] boiler mind somewhat oily water -- there were never any deposits in it, even with gross over-oiling, probably because of the high velocity of the minimal water inventory in circulation."

Peter

For anyone interested, here are a few pages on oil separators. http://www.stanleysteamers.com/paper...ATOR_FINAL.pdf
http://www.stanleymotorcarriage.com/...atorDesign.htm
And here is the centrifuge I mentioned, on a steam converted vw bug engine. Its surface area is like a coffee pot, and with modest insulation, such a one can be kept too hot to drink for a long time.
http://www.youtube.com/watch?v=mOsEYpIQomE

By the way, the topic is "steamless steam engine" and the first post is about the Stirling and Ericsson cycles - it seems rather wide open but the target seems to be evaluating engines that can use carbon neutral fuel. Ideally some of that fuel is created onboard, by wind, waves or sun, if so, maybe ammonia generation would be worth investigating. Generation is much more wasteful than using batteries, but energy density is about half that of diesel, similar to wood. It can be used in heat engines or fuel cells, which might be more efficient. It would be interesting to know if converting the wood/biomass/biodiesel to hydrogen and using it in a fuel cell is more efficient than to utilise them in a heat engine...

Originally Posted by sigurd

Peter Brow is designing a steam car. Here is what he wrote over at steamautomobile.com phorum. I bolded some text.
..

Unfortunately that guy seems to have quite limited knowledge on the subject matter.
This for example is just wrong:

There is also a school of thought that small amounts of oil in practical steam/water systems provide valuable protection against corrosion and scale/deposit buildup, while allowing use of less expensive and more easily-worked materials and simpler/cheaper equipment. IE, perfect oil/water separation, or oil-free operation, is not necessarily the best way to go.

In a closed system like the Rankine cycle engine we are talkng now, even 1ppM s too much.
A wet steam system in our old Tugboats does accept that, no doubt.

The best sep. I have found and operated by so far is the combined baffles, cyclone, centrifugal separation.
The problem I pointed out, the energy loss, is a must! If the steam pressure/temperature is too high during separaton process, oil will pass the system as gas.

But you are right, we are a bit off topic now. And the Rankine cycle engine here is claimed to run without oil.

Regards
Richard

[sigurd]

Originally Posted by apex1

The average yacht Diesel is still in the 30 something ballpark.

Ok. Harry Schoell claims the Cyclone is over 30% efficient. I remember the claim for one of the thermoacoustic electrical generators were about 30%. The latter two are more silent and simpler and hopefully require less maintenance and last longer. I don´t know much about fuel cells but according to wikipedia they are much more efficient.
I believe small turbines´ efficiency suck, but detonation and or combined cycle (waste heat recovery) may change this...
Detonation turbines: http://www.worldkar.com/html/turbinepower.html
http://www.ttengines.com/technology.html

[sigurd]

Originally Posted by apex1

In a closed system like the Rankine cycle engine we are talkng now, even 1ppM s too much.
A wet steam system in our old Tugboats does accept that, no doubt.

The best sep. I have found and operated by so far is the combined baffles, cyclone, centrifugal separation.
The problem I pointed out, the energy loss, is a must! If the steam pressure/temperature is too high during separaton process, oil will pass the system as gas.

But you are right, we are a bit off topic now. And the Rankine cycle engine here is claimed to run without oil.

Regards
Richard

Well, I think the SES engineer´s statements should be lent some credit. However, Schoell stated that on high temperature/efficiency engines the oil separation remains a problem and that they would not have continued development if they had not found a water-lubricated solution. IIRC the Cyclone runs at >2000 psi.

Is the separator you mention before the condenser?

I appreciate the discussion. I hope the thread starter feels free to shut us up or reiterate the desired topic if he wants to.

Originally Posted by sigurd

Well, I think the SES engineer´s statements should be lent some credit. However, Schoell stated that on high temperature/efficiency engines the oil separation remains a problem and that they would not have continued development if they had not found a water-lubricated solution. IIRC the Cyclone runs at >2000 psi.

Is the separator you mention before the condenser?

I appreciate the discussion. I hope the thread starter feels free to shut us up or reiterate the desired topic if he wants to.

After condenser, the more common way. I never had a overheated steam system, so, cannot comment from first hand knowledge about them. But at 137bar we are not in that range with the Rankine engine. (Schöll)

I did not contradict the SES engineers, but what seems to be nice in one setup, is a catastrophe in the next. Just the difference between a old boiler and a renewed one can drive you nuts!
Steam propulsion is as complicated as nuclear power, although it does not look so.

Regards
Richard

[sigurd]

Regarding power density, Schoell said:

"The MKV is rated at 100HP with high efficency numbers increasing the cutoff will increase the hp thus the power density but the efficency will drop. This is OK for exceleration but not for constant speed but this will easily beat an IC engine. The MKV weights in at about 340 lbs all up complete heat exchangers pumps blowers condencers and all controles It is 24" high and 28" in diameter. the engine for Chuks LSR car will have a double heat exchanger and run a slightly longer cutoff to increase the hp to 180hp. . It will be only semi condencing so it will still be almost the same height."

Originally Posted by sigurd

Regarding power density, Schoell said:

"The MKV is rated at 100HP with high efficency numbers increasing the cutoff will increase the hp thus the power density but the efficency will drop. This is OK for exceleration but not for constant speed but this will easily beat an IC engine. The MKV weights in at about 340 lbs all up complete heat exchangers pumps blowers condencers and all controles It is 24" high and 28" in diameter. the engine for Chuks LSR car will have a double heat exchanger and run a slightly longer cutoff to increase the hp to 180hp. . It will be only semi condencing so it will still be almost the same height."

I have not got that last comment. What has semi condesing to do with height?

Yes, the relation between power density and efficiency is a finicky part in steam propulsion of recent generations.

I assume we will see some sort of a renaissance when these new developments grow mature.

Regards
Richard

[sigurd]

I suppose the 180hp one is using the same condenser as the 100hp, so still same size, but can´t condense 180 hp worth of steam, so spills some of the water. Just a guess.

[cthippo]

Originally Posted by Petros

Par,

that sounds like an interesting contraption, do you have any pictures of it? We do not get enough sun up hear in the PNW, so solar power would only work for about 1/2 to 1/3 of the year.

I'm not so sure about that. I have a friend who installed a solar hot water system and he gets near boiling water out of the collectors even on cloudy days and he's north of you (Whatcom Skagit border).

Tesla turbines can be super loud, but the one I saw was running at something like 11,000 RPM.

I was toying the other day with the idea of using a Tesla turbine in place of a paddle wheel in a small multi-hull boat. Does anyone see why that wouldn't work?

[hawkerdonkey]

Hello to all,

since it has been quite some time ago when this thread petered out, allow me to put some coal on the fire (!?) and suggest the following outlandish idea;

Scroll down a bit on the page and you will find a steam generating rocket.
There must be some way we can make this work under a boat, after all, torpedoes run on the same stuff!

http://www.tecaeromex.com/ingles/RH-i.htm

The propellant expands by 5000 times after passing through the catalyst. 197hp from such a small rocket is quite something. Either use it underwater or in combination with the cold-section of a turbine engine?

Let me know what you think.

H'donkey.

[Boston]

hey Honkey that's pretty cool

[hawkerdonkey]

Thanks Boston,

as they say, there is no replacement for replacement I'm well impressed with his workmanship. Btw here is the link to the inner workings of a H2O2 powered Swedish torpedo, it gets interesting from 3:02.

http://www.youtube.com/watch?v=j3hLwTPq3hc

Lets make this work!

Happy landings,

H'donkey.

[cthippo]

Look at what seabirdship is doing. His thread is the one about hybrid pulse DC something in this same forum. He's using 90% H2O2 and waste motor oil for a very innovative propulsion system.