Stirling engines for the third world

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stan.hornbaker
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Response to Stirling engines for the third world

Post by stan.hornbaker »

As the last poster noted this web site and the forums are for discussion of Stirling ENGINES.

Be forewarned.
Any off topic posting(s) are subject to deletion without notice.

There is a Hot Air Engines forum on Yahoo which would be appropriate for such discussion.
bptdude___2569
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Last Name: McLean

Response to Stirling engines for the third world

Post by bptdude___2569 »

Here is something about Stirling engines.

http://www.ctamachinery.com/

I went to this:
Connecticut Antique Machinery Association show

Mostly they had steam engines, but they had one working Stirling.
I stood there and watched it.
They had a small firebox underneath, and it cranked quite well.
It was probably 100 years old.
This could easily drive an electrical generator for my house.
I could feed it coal or firewood.

As I just stood there staring at it, all I could think of is why why why can anybody just make these things again.

Why is it so hard to find or buy a Stirling engine?
Why do so many "experts" say it is not possible to build one?

Somebody throw me a clue.

By the way, it is a way cool show, they have it once a year.
The steam engines were very interesting.
I did find people that had old small steam engines they might sell.

You can't even find these steam engines new, oddly too.

There it was though, the Stirling engine, the mythical unicorn, right in front of me, chugging along. It was so frustrating.

cchagnot
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Last Name: Chagnot

Response to Stirling engines for the third world

Post by cchagnot »

Joe,

I have perhaps eleven or twelve various antique Stirling engines in my collection. Every one
of them still run. Most are kerosene fans and do a nice job of wafting warm smelly air at
one. Even the large Rider-Ericson that I have that pumps water works. BUT.....They
actually produce very little usable power. The fans probably around 10-30 watts, if that.
The Rider maybe 50-100 watts. Without regenerators they're also terribly inefficient. You
might be able to run something like a small LED light with one but not much else.

Real Stirlings are alive and well however. The price of oil has finally made it very cost
effective to bring the ST-5 into mass production and we're presently costing for around
10,000 engines per year, with the manufacturing costs somewhere less than $3,000. I
have posted a number of videos on YouTube showing the ST-5 running in Korea and our
lab back in the States. With any luck (and a lot of hard work) one will be able to buy an
ST-5 in the next couple of years or so. I'm in Asia now working on getting it into
production.

Here are a few links to the videos of the ST-5 I put on YouTube.

http://kr.youtube.com/watch?v=r6zMCF-IKco (Music from "Terrapin Station by the
Grateful Dead) Who else????

http://kr.youtube.com/watch?v=7574w2RMeO4

http://kr.youtube.com/watch?v=24SvyVSIcYY

http://kr.youtube.com/watch?v=yYXMN-jFe-k

http://kr.youtube.com/watch?v=EDWhNzggnO8

The engine pumping water in Korea; http://kr.youtube.com/watch?v=NEg7oNXf0-o


Catherine
stan.hornbaker
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Response to Stirling engines for the third world

Post by stan.hornbaker »

According to recent scuttlebutt a 2-HP self-pressurized Stirling engine will be in production by the end of the year by in or near Huntsville AL.
stan.hornbaker
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Response to Stirling engines for the third world

Post by stan.hornbaker »

Joe McLean: You must have been looking at a Water Pumping Hot Air Engine designed by John Ericsson, not a Stirling engine.

Wikipedia has an article on him at:


Look through the links at and search via Google. There are differences in the operating cycles of Stirling and Ericsson engines.

acacialiberty
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Response to Stirling engines for the third world

Post by acacialiberty »

I have been trying to research applicability of Stirling engines for Botswana. My current profession is Building Economics.

I have worked in many African countries including Nigeria. NigeriaÂ’s electrical grid is a mess and all activities require gensets. Most of the idea that if America isnÂ’t using it then it is 2nd rate stands as an acute marketing observation.

Living in Botswana we have occasional power cuts due to our reliance of 30% of our needs from neighbouring South Africa that has let itÂ’s system go to pot and is trying to make good.

Botswana we have no shortage of solar energy but most villages donÂ’t have access to power. There was a huge surge in demand for gensets some two years back when the power failures started. However most of the sets were from China in whatever flavour you want but for reliability.

Refurbishing a building to be viable is closing the door after the horse has bolted. Designing it to use LED and alternative energy from the start can mean removing 90% of the electrical infrastructure hardware including smaller gensets using much less fuel. The biggest saving is in the maintaining of worker productivity ( a shadow cost).

I am looking to use a 90f natural heat differential (possibly using evaporative cooling and solar heating to aid this). No it canÂ’t come close to the cost of grid power however in terms of getting a good one in place in a properly designed building I believe that the savings in man hours and genset operations may well show a better picture. But for tropical countries the natural heat differentials are a poor start.

As with solar energy the electricity usage of the operator needs serious reconsideration, usually from the design of the original building. In addition I just still canÂ’t make any system work long term using batteries which is why I am shunning solar cells. Solar hot water yep but batteries nope.






yanto_go
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Response to Stirling engines for the third world

Post by yanto_go »

In response to Timothy Hosking: instead of battery, can we use compressed air as a mean for energy storage?
stan.hornbaker
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Response to Stirling engines for the third world

Post by stan.hornbaker »

Can compressed air be used as an energy storage method? YES if you can tolerate the losses due to cooling during storage and reheating on expansion or losses therefrom.

It is NOT a very efficient energy storage medium.
shannonkeyannon
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Response to Stirling engines for the third world

Post by shannonkeyannon »

Hi all,

Fantastic thread and couldn't help but read the while thing! I hope some of you are still out there :)
I too am edging my way into some of the practical problems facing developed and developing nations. I have my own projects that I am working on, and cannot wait to get a prototype up and running.
I feel like any day now I will read about someone who has just completed trials. It would not be the first time I have "invented" something just by looking at the needs and working through the
problem - just to find that it has already been done.
The reason I am putting this up is not to draw attention to myself, but to explain that I love multi faceted design work and would be more than happy to be involved in your discussions. This area
hold particular interest for me not only because is a good thing to do, but because there are so many competing factors; political, logistical, technical and environmental.

For the problem at hand,
Catherine and other in the field - I would like to hear more about the reasons your projects struggled. It does not sound like it was purely technical at all.

I found the question about building a massive unit even though power expectations were low, interesting. No takers? What is it that limits building a large engine? In regular internal combustion
terms you add more cylinders and increase displacement to increase power (and fuel consumption) but provided that you could supply enough heat to the hot side what else stops a large unit from
producing usable power?

Could I also suggest that heat flow cannot be described in terms of temperature either. That is only part of the equation. Temperature is the effort that overcomes the resistance - in this case
the thermal conductivity of the material the engine is made from. A thermal gradient builds up across the material and passes its heat to the working fluid and so on, which you would all be
familiar with. A very wise and cunning engineer I used to work with once compared a massive LPG burner we were using and an acetylene torch we used to light it. The torch was much hotter, but the
LPG burner was producing much more HEAT...
The thing that gets me is that making the engine bigger in this regard actually helps by giving you a greater surface area to transfer heat to/from (can't forget the from)... What am I missing?

Anyway, thanks for the great read, I will be spending a lot more time around these pages. Great to see like minded people out there. Only crazy if you're alone right?
bptdude___2569
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Last Name: McLean

Response to Stirling engines for the third world

Post by bptdude___2569 »


Shannon, thank you for your post. I would like to say we are all aware of the difference between heat and temperature, but sadly there always seems people who are not as familar.

Many people cite sources of extra heat they would like to make good use of. Often the temperature is not high enough to drive the conversion device we call engines to produce practical work.

This is usually the problem with practical Stirling engines, but there is SO much more to that story. If you explore the various threads on this web site, the picture should become clear.

Regards, Joe
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