Closed chamber Stirling engine generator.

[Groundloop]

@dutchy1966,

Thank you for your ideas. Yes,  Fresnel lenses will work. But a parabolic dish is not expensive/complicated.
Buy a multi head (wide horizontal) ready made disc. Glue on aluminium sheets. Put one one layer of
clear sealer, and there you go. You can also use a normal (very cheep) offset antenna (for satelite TV receivers)
covered with alum. foil and clear paint.

Groundloop.

[Groundloop]

@tinu,

Thank you for you detailed post.

   The problem I see with my design is the lack of flywheel. But do we really need
   a flywheel? We can use other means of providing the flywheel effect. I have a coil (or coils). There is no law in nature
   that prevent us from using a tiny part of the power to make the flywheel effect electronically. (Or by magnets?)
   By doing that we can get the compression cycle to the engine.

   My drawing is a very inaccurate idea drawing only. It is there to show us that it is possible to convert the piston movement
   direct to usefull energy without any other moving parts. Since there is no need for a flywheel the design of the generator will
   be very compact and simple. It will also be airtight so that other gasses than air can be used inside the motor.

   Me living in Norway is besides the point. It will be dumb to use this is Norway anyway because we have all the energy we need
   from water power plants etc. My main goal was to spread the idea to improve current Stirling solar plants. My second goal was
   to see if my method works. I already know that by using normal Stirling engines and generators you can get the double of energy
   output compared (area wise) to Sun panels.

   Again, I must stress that my drawing is not an engineer drawing but a simple idea drawing to show that it my be possible
   to get the energy out of the motor with a magnet/coil instead of a flywheel and generator.

Placed at the focus of a parabolic mirror a Stirling engine can convert solar energy to electricity with an efficiency better than non-concentrated photovoltaic cells. http://en.wikipedia.org/wiki/Stirling_engine

Groundloop.


 

[Gearhead]

@Gearhead,

Thank you for the information. Do you remember where or who? Maybe a web link?

I have decided to try out my idea, making a prototype. I will use a 46 cm parabolic mirror.
I will also use water cooling on the "cold" part of the engine. The maximum temperature
with a small parabola like that will be 400 - 600 degrees Centigrade on the warm side of
the motor. Depending on how much help I will get on this forum my project will take from
some few weeks to a year to complete. I have computed the total cost of this project
to be approx. 4500,- NOK. (865USD). My goal is to beet the output of a solar panel of
equal area as a 46cm parabola.

Groundloop.

A fellow named Beale invented the free piston Stirling engine.  Here is one for sale.

http://www.stirlingengines.org.uk/manufact/manf/usa/new6.html

This thermoacoustic engine seems to be a better way to go.
http://www.io.com/%7Efrg/tac.htm

There is a video of a working machine on the main page here.
http://www.io.com/~frg/

More Stirling info
http://www.sunpower.com/lib/sitefiles/pdf/productlit/Engine%20Brochure.pdf

[Groundloop]

@Gearhead,

Thanks. 

After seeing the TAR and the TAC systems, I start wonder why we still use those ineffective internal combustion engines.
I has become quite clear to me that the Stirling engine method is superior to any other engine in many applications.

As an energy converter, the MEMS-TAR can be printed in ganged arrays on a single panel substrate, complete with circuit wiring and power conditioning circuitry, to convert solar energy to 60 Hz electrical power at two to three times the efficiency of photovoltaic cells, and at 5% of the cost. It can be embedded into interconnecting roofing shingles for residential power--shingles that building contractors can install on new or existing homes. In large arrays, it promises a new era for independent electric utilities. Plant expansion can now be done cheaper and with no increase in fossil fuel consumption and no emissions control costs. It can also be used to convert waste heat from boilers, industrial processes and engines back into useful electrical energy.

Groundloop.

[Gearhead]

@Gearhead,

Thanks. 

After seeing the TAR and the TAC systems, I start wonder why we still use those ineffective internal combustion engines.
I has become quite clear to me that the Stirling engine method is superior to any other engine in many applications.

Groundloop.

Both Ford and General Motors have built prototype Stirling powered vehicles and done extensive testing with them.  They were 10-20 percent more efficient than ic's.  There are two major drawbacks to efficient Stirling technology.

  One is that a Stirling engine takes time to start up.  Ford's prototype car took 30 seconds to develop enough power to pull away from the curb.  Pulling away from the curb does not imply that full power is even close to being avaiable.

Number two is that an efficient Stirling requires exotic expensive material that can stand the high temperatures and pressures. 

The third problem is that it takes money to retool for a new technology.  Why change when people are still buying the same thing they have for a hundred years?  Chrysler company built 50 turbine prototypes in the 60.  They did the same thing with them that General Motors did to the electric cars they made for California.  Keeping the status quo keeps everyone happy raking in the cash.

There is a Stirling powered airplane account on the web.  It takes time to start up, but they use a bypass to reduce power so that the heat energy is available in case they need to power up and go around during a landing.   The engine is reportedly extremely smooth and quiet.