Heat Engines

[vteco]

BTW
1. I was thinking of a muffler as a tuned pipe. Hence the collector. The colector (exhaust manifold) on mine had a dual purpose as cladding to retain cylinder heat. Steam engines (unlike IC engines) like hot cylinders, so insulation (cladding) was traditionally used. I thought I'd do them one better by using the exhaust heat to insulate.

2.) Westinghouse type steam engines come in all sizes. The term generally refers to a high speed steam engine of two cylinders with a block arrangement similar to a modern IC engine, IC style connecting rods and an oil pan. Large variety of different valve types were tried.

My Westinghouse type full sized steam engine isn't huge in size. Slightly smaller than my 6 HP Listeroid single diesel generator engine.

[vteco]

Model versions of the Westinghouse type steam twins were pressed into service in WW2, reputedly as spy electric generators. See here:

https://alcofirefly.com/

[Logic]

Originally Posted by vteco

Exactly, Logic!

heh, now you see the need for a muffler on mine. You could maybe run the exhaust underwater, like a conventional outboard. I wasn't nearly at that point yet, though. Just building the engine.

I've been building up little bits and pieces of information about high speed flash steam engines for years. Best description of the history and mechanics etc (of both small and large) is the book "Experimental Flash Steam" by Benford.

I have tons of past issues of Model Engineer the British magazine, dating back to 1890's. These racing hydroplane engines are an amazing historical topic to me. Just a handful of people have ever pursued it, but their innovations down through the decades (well century, actually) are really awe inspiring.

Anyway, the one I was building was to be a detuned version -- I thought about it as both a small outboard motor (I was gioing to use an old Elgin outboard motor I have as the lower unit) and as a small stationary generator for camping.

An alternative plan for a boat motor was to do it as a generator for an electric trolling motor rig.

I was thinking it would be really cool if you could use a supply of twigs and pine cones etc, found on shore as fuel, as you went.

If ICE are said to be 30% efficient; What kind of efficiency does one see from these small, high rpm steam engines?
I suppose it all depends heat insulation and using multi, 2nd piston bigger than 1st designs?

Google AI says; By the early 20th century, steam engines in factories, ships, and locomotives were around 25% efficient.
That's not bad and these are probably better?

I'm thinking a steam-electric hybrid might be interesting:

Now your outboard runs while the boiler is still warming up and you have a silent mode for most of your fishing.
You get somewhere to store power while the boiler is cooling down (after arrival etc)
You have your outboard/genset/motor combo.

ie: There are more advantages for 'light steam' when combined with electric than there are in petrol electric hybrid boats etc..? (where water and wood is plentiful)

Is there a site on the design and construction of these small high rpm boat etc engines?

[vteco]

Logic, I don't think the steam racing hydroplanes are very efficient in terms of heat loss, etc. But they're designed for only one purpose. Go as fast as you can for a very short time. They run up to 4 blowtorch type kerosene burners going full to heat stainless steel tubing boilers to red heat. We're maybe talking superheated steam. I think pressures are more than 1000 psi.

There are no websites that I know of that are devoted to flash steam engine construction, though there are sites devoted to building model engines in general, and high speed steam flash engines may appear there rarely. Really the best resource for building them is the book Experimental Flash Steam. Out of print, but used copies are available. Really good book.

When people talk about efficiency I think it's important to think about what reference frame they mean. In my case a gasoline engine generator might be technically more efficient, but a steam engine that was less heat efficient but burned a readily available renewable fuel found in abundance nearby is a different kind of efficiency compared to purchasing a fossil fuel that had to be pumped out of the ground, refined transported, put into tanks, then pumped into a gas can, then driven to the boat.

I think it's important to think about the big picture when it comes to any particular situation involving efficiency of energy usage.

Of course my rowboat is even more efficient. It's fueled by a sandwich.

[Piotrsko]

How many sandwiches to the furlong per fortnight?
Steam locomotive went to oil because the fuel was significantly more energy dense. Per cubic ft, oil has maybe a 4 fold advantage over wood, perhaps double that of anthracite. And you dont require a fireman stoker

[vteco]

I don't think locomotives should be run on coal.

I think a small boat I build should. I think a camping generator (if one wants one) would be fun to run on twigs and pine cones.

I eat one sandwich for say 6 hours on the water. Since I'm usually fishing it depends on how far the fishing grounds are away, or if I'm trolling or casting or anchored. I can row 3 mph steadily when I'm moving to a spot. 4 mph is sprint speed. I have no problem covering a couple miles to get some place I want to fish.

I once rowed across Lake Champlain from Burlington, Vermont to Essex NY, I believe about 13 miles, in 3 hours, just to do it one Sunday morning. I had lunch afterward. I'm 75.

[vteco]

If you had a steam engine driven generator connected to your house, and lived in a remote forest, and you had 50 dollars only to spend on consumables to hike in and live with for the next 30 days:

Would you buy
1.) 50 dollars worth of oil
2.) 50 dollars worth of coal, or
3.) 50 dollars worth of food?

[Isaac Zachary]

Originally Posted by vteco

In an ideal world you'd want the densest fuel possible, because they are the most compact, and compactness is an advantage in a vehicle.

Nuclear powered vehicle?

On another note, I love steam and stirling engines.

[freebeard]

I think a small boat I build should. I think a camping generator (if one wants one) would be fun to run on twigs and pine cones.

Clad the boiler with thermoelectric transducers.

[Logic]

Originally Posted by vteco

Logic, I don't think the steam racing hydroplanes are very efficient in terms of heat loss, etc. But they're designed for only one purpose. Go as fast as you can for a very short time. They run up to 4 blowtorch type kerosene burners going full to heat stainless steel tubing boilers to red heat. We're maybe talking superheated steam. I think pressures are more than 1000 psi.

There are no websites that I know of that are devoted to flash steam engine construction, though there are sites devoted to building model engines in general, and high speed steam flash engines may appear there rarely. Really the best resource for building them is the book Experimental Flash Steam. Out of print, but used copies are available. Really good book.

When people talk about efficiency I think it's important to think about what reference frame they mean. In my case a gasoline engine generator might be technically more efficient, but a steam engine that was less heat efficient but burned a readily available renewable fuel found in abundance nearby is a different kind of efficiency compared to purchasing a fossil fuel that had to be pumped out of the ground, refined transported, put into tanks, then pumped into a gas can, then driven to the boat.

I think it's important to think about the big picture when it comes to any particular situation involving efficiency of energy usage.

Of course my rowboat is even more efficient. It's fueled by a sandwich.

Yes the racing boats etc would be all about lightness and max HP for a short while.

My wondering about efficiency is based on one wanting to be 'green' if one can.
But yes; free fuel wins out if space and weight and especially laziness isn't part of the equation.
I have no idea how the fire smoke might be cleaned up a bit? Centrifuges? Bubblers?
That would require some forced air, but might be an option.

Here (Africa) anything and everything that burns would be fed to such a steam engine.
Old plastic, tires, dry turds, animal skin and bone, you name it!
Foresight and technical ability was simply not an evolutionary requirement on the equator where there is always warmth and some fruit or other in season.
It's simply not 'the place' for civilized people and I was very stupid to get caught here.
Hence my 'local' thinking that steam needs to be 'greened' some / efficient.

I like your idea of using a tuned pipe on a steam engine.
I didn't ever think "tuned length exhaust" and "steam engine" would be in the same sentence! But yes; it would work!

I think even David Vizard's Pressure Wave Termination Box would work.
This PWTB is a way of 'fooling' the exhaust into thinking its escaped into free atmosphere, so that the muffler/s don't negatively effect the tuned length.

If I understand you correctly; you were then thinking of putting the engine inside the/a 'muffler' as a means of keeping the engine as warm/efficient as possible?
I wonder if plain old insulation (glass wool etc) isn't the more efficient and practical solution:

While the exhaust steam is hotter than ambient, there is a hell of a lot of 'flow' in it and that might just result in the engine being cooled down more than it would be with plain old glass wool or some-such insulation..?

Possibly bubbling the exhaust through your feed water is a better way to both muffle the noise and recapture the wasted heat..?

(Bubblers are an overlooked means of muffling in any engine IMHO.
ICEs produce a liter of water per liter of gas burned, yet...)

I can imagine that the design and building of steam engines is practiced by people that are pre internet and computers .
It's a shame, as that means the knowledge wont be passed on to younger generations, just as the oil industry would like!

The book etc you mention deserve to be scanned and put online IMHO.
The knowledge of designs and what metals work together and lubs etc and safety measures etc-etc is an 'art' humanity doesn't know it doesn't want to lose!

What are your thoughts on constructing safe boilers?
Can gas bottles be used safely and effectively/efficiently? Or is a stainless steel heat exchanger the way to go?