Stirling Engines

[Cogman]

I was Watching the History channel's "Modern Marvels", and they where doing a show about engines. On that intrested me was the Stirling Engine. They run not on gas, or electricity, but heat diffrences. The history channel showed a demonstration of them running off the heat from a hot cup of coffee, but it could also run off of a cold pack of Ice. One even ran off of the heat from your hand. So, I was woundering, What have you all heard about it? Do you think there will ever be a practical application for it? (It looks like I could make a good Computer Fan, so Im going to post a post about this in the Cooling fourm, not the same mind you) [edit]Fixed the Stirling spelling [/edit]

 

[Smilin]

I thought I read there was some interest in using these for generating electricity - having numerous local power plants instead of large regional ones. Sterling engines aren't very powerful at all especially considering their size/weight but they are very very efficient. So efficient that it only takes small amounts of energy (solar or whatnot) to run them.

 

[pm]

I have a couple of sterlings that I built myself back when I went through a phase in my hobbies of motor building and engine tinkering. They are pretty neat, but the amount of power output makes them pretty impractictical for any application that I could think of - particularly with less than boiling temperatures to work with.

Walking Beam Tin can sterling plans
More expensive kits that can be powered by the heat from a hand, or a cup of coffee
A whole lot of sterling links from the Sterling Engine Society USA.

 

[zsouthboy]

"impractictical" eh?



I am surprised I have never even heard of this before... interesting..

/me goes to google

 

[dkozloski]

General Motors has had a Sterling engine research program on and off for years but it never seemed to go very far. Since they got bitten so bad by their electric car efforts it is going to be very hard to convince anyone on this one.

 

[f95toli]

Sterling engines are used in modern submarines. They are almost as quiet as nuclear subs.

 

[sgtroyer]

What produces the heat then, if they're not nuclear?

 

[f95toli]

You can get more info if you follow the link below. The heat is generated by burning pure oxygen and diesel fuel in preassuriesed combustion chamber<FONT size=1>.
Link to Kockums</FONT>

 

[Spacehead]

There's a short blurb in the new Discover magazine about these. I had never heard of them before either.
According to the article, DEKA Research plans on using it to power the next generation of the Segway.

 

[Howard]

Damn, everybody who's posted in here spelled it wrong. "Stirling"

 

[Shalmanese]

Hmm... The 2nd law inherantly limits the efficiency you get from a given temeperature differential. The higher the differential, te more efficient you get. So wouldn't a stirling engine be inefficient by definition?

 

[Cogman]

Originally posted by: Shalmanese
Hmm... The 2nd law inherantly limits the efficiency you get from a given temeperature differential. The higher the differential, te more efficient you get. So wouldn't a stirling engine be inefficient by definition?

Could you post the 2nd law? (Im guessing its of Thermal Dynamics).

 

[f95toli]

As far as I remember a Stirling engine is very efficient and actually very close to the Carnot limit.

 

[rgwalt]

Originally posted by: Cogman

Originally posted by: Shalmanese
Hmm... The 2nd law inherantly limits the efficiency you get from a given temeperature differential. The higher the differential, te more efficient you get. So wouldn't a stirling engine be inefficient by definition?

Could you post the 2nd law? (Im guessing its of Thermal Dynamics).

Cogman- Search for the 2nd Law and Carnot cycle on google. The maximum efficiency for an engine is (Thot - Tcold)/Thot, which is also called the Carnot efficiency. The 2nd Law of Thermodynamics states that the entropy of a closed system must increase. Effectively this means that you cannot completely recover the energy you put into a system.

R