Stirling engines for the third world

[stan.hornbaker]

There is a group of individual Stirling entheusiasts from all over the world, with a site on yahoo, who are working on a 2HP Stirling engine.

[westlund.johan]

I am an electrical engineer that is becoming more and more frustrated about not finding any really worthwhile engineering problems. Today I realised that perhaps dedicating myself to the problem of very smallscale electrical production would be something that would help the world rather than fueling the consumerism mass-psychosis. So here I am, and its apparent that the Stirling engine might be just what im looking for. Right now, my grasp of the Stirling engine comes from labs in thermodynamics in college, but I hope that will change soon. If there is any way you think I can contribute to a project, I will be happy to give it a go.

[njimihunt___5788]

Thank you, Johan Westlund, for offering help for small scale work. I have a piece in this third world section, and also a few pictures on another page showing my copper pipes and clear plastic hose version of a Stirling liquid piston engine. It has a seven metre tuning column, which takes up a bit of room. Now I am playing with books from the library and looking up the internet to try to find out who makes linear motors and linear electric generators. So far I have found a US company called Baldor but have not emailed them, and some mention of marine wave machines which generate from upward and downward thrust. My books say that Faraday's law requires SPEED as well as a lot of coils of wire, and a strong magnet and since I am not going to get a lot of speed from a reciprocating motion of 10 to 20 cm at about a second's interval I am looking up some of the other tricks like special materials to use in the core of a solenoid.
When I can get my little machine working I will make a bigger one, still using firewood as the heat source. I would like to be able to charge 12 v batteries. (I also wonder about compressed air, but that is not your field.) Some of my friends are farm foresters and some day may be looking to power machinery from their own waste products. Jim Hunt.
PS I have corresponded with Peter Fette of Germany who describes his double action Stirling engine and seems to have patented electric piston gear and generating output. See his account under power producing engines. He seems to be aiming at using hot water from solar schemes.

[aleurite]

Adapting a synthesis of existing technologies would make the exercise less expensive...

For example the VW boxer engine with one side being hot and the other cold.

Terraniageoff from the sydneypeakoil site has a thermal solar cooker that can melt basalt - 1400 degrees C...

If solar could be used to heat up rocks from which is drawn the air for the hot side, and a water pond for the cold side - linked with small solar pump for air cooling water you would have an engine that would operate 24/7 and if used to generate electricity it would become useful for not only the third world but for ours in the face of the immenent peaking of global oil supplies....

Technologies out there - what are the problems - ?? Would not the engine itself be enough to pump the air from the hot rocks? and allow the engine to operate at normal temperatures?


Cheers,

Sololeum

[scott___8035]

We are working on this very problem. We have been creating a small ethanol/bio-deisel production for rural Borneo and Africa. We have been wrestleing with the issue of an open flame for the distillation column, and have come to the conclusion that evac. tubes compound parabolic reflectors will do the job nicely.

In the process we realized that a we were creating a power plant and could use the excess heat to produce electricity through steam. Again an engineering and safety issue with high maint. and steam pressure. So I ran across the Stirling engine....and you all. Can we create a solar array of evac tubes w/reflectors that can produce 15-21000 btu's an hour (for an 8 tube array at full sun) and temps up to 250C. Can we create a combination of these technologies that will make a Solar Energy Power Station (SEGS) of 10-50kW? We would use a Stirling to generate the electricity and storage of heat in rock (gravel) columns in the ground with a heat pump, to keep the Stirling going in non-sun and at night. What are your thoughts guys?

[wilting]

After reading al the intresting, and differend comments on the 3.world topic i think that the time could be right to start discuse how to rais foundings, and put the ideas into action . I think this is the way to go.

[bptdude___2569]

Forget the third world, I'm interested in my world. I can purchase outdoor wood furnaces that will generate tremendous abouts of heat. I live in a state that forces by law the power grid to buy back electricity at a fixed rate. I own many acres of land with large trees I can produce firewood with.

Are you telling me nobody in all the Stirling engine world can do the math and produce a Stirling engine I can purchase to fit this money generating application?

- Joe McLean

[vminnen]

Are you all aware of this product: Sun Machine?

[cchagnot]

Years ago we designed and put into production in India a 5 HP biomass fired Stirling for
developing countries. (Please, third world is sooo not cool). Anyway for a bunch of reason
primarily due to lack of funding we eventually had to shut this operation down.

The key to Stirling Engines in these places comes down to cost and productivity. One
reason the project died was that oil costs were too low for a long time, not because the
engine didn't work. Now, with oil at somewhere over $60 per barrel it makes even more
sense.
One of the keys to making a successful project is to design something that can be
manufactured locally thus providing the local economy a boost as well as making it more
possible to have an affordable engine.
We're currently putting Stirling Technology's 5 HP engine, with improvements, back into
production. Looking at significant numbers, we are estimating around $5,000 per engine.
That's still hard for many developing country farmers to afford.
You can go to http://www.Stirling-tech.com for more info on the engine.

Catherine

[stan.hornbaker]

Catherine Chagnot, suggested looking at the ST-5 engine in the previous response. The most recent information on the South East Aisian Rice Hull Project, generally available, is in the form of a book "How I Built a 5HP Stirling Engine" sub titled "The Story of the Rice Hull Project in Bangladesh." Written by Dr. L. Merrick Lockwood. His final recommendation was to build a Ross linkage drive with two cylinders. The ST-5 is no longer in production and the patent rights have been sold.