This has nothing to do with electronics or even electricity, but it is the sort of thing that really grabs me.

I stumbled across a short book by Andy Ross on making Stirling engines with some power (i.e., 200 to 230 W). His dedication to that goal is fascinating, not to even mention his machining skills. It is a free download. I checked it with Avast, and it is virus free.

http://stirlingbuilder.com/ (You need to scroll to Andy Ross)

John

 

I have always been facinated by stirling engines!

There is a you-tube-er who makes them from discarded tin-cans and clothes hanger wire.

Low power, (very) but quite interesting nonetheless.

I will give this a read.

(AVG gives this a virus-free also)

 

At one time you could buy fans, like a desk type personal fan, powered by sterling engines. I think there were other appliances too, but the desk fan is the one that sticks in my memory.

 

http://www.odts.de/esg/ST5engl.html

a nice example.

 

@Kermit,

Nice link. Home heat and power -- that is exactly what I am looking for. I have an outdoor woodburner with water heat. I want the heating function to be independent of the power grid. My thought is to use a Stirling to charge batteries that would then run the two pumps needed for the house. Less than 1 HP total. So, if the pumps operate 25% of the time, I need significant, but not unreasonable power from the Stirling.

John

 

Kermit's link shows a beautiful machine but I don't understand the 225g/hr of propane to obtain an output of 300W. Is this 225 grams per hr?
At first glance I thought it was gallons per hour, but I'm billed for natural gas by the cubic meter.

 

Thanks for the link, I have half a mind to build one of these now and run it off the exhaust heat of my laptop (theres plenty of it), come up with a useful, low power application... desk fan sounds good
(just in case anyone was still unsure, verizon didn't detect any viruses on it)

 

Hi soundman, LPG is sold in cylinders by weight or in vehicle aplications by the Liter.

 

Thanks, Daryl. It must be gallons then.

 

Thanks, Daryl. It must be gallons then.

Do you mean gallons of liquid or gallons of gas (i.e., volume of propane gas)?

I think the g stands for grams. 225 grams of propane is 5.114 mole, which is about 115 liters of gas at STP. 115 L = 0.115 m^3 = 4.1 ft^3

The conversion for propane to BTU is a bit higher than for methane to BTU, because propane has three carbons. The literature value is about 2500 BTU per ft^3. Thus, 4.1 ft^3 of propane is about 10,000 BTU.

John

 

Do you mean gallons of liquid or gallons of gas (i.e., volume of propane gas)?

I think the g stands for grams. 225 grams of propane is 5.114 mole, which is about 115 liters of gas at STP. 115 L = 0.115 m^3 = 4.1 ft^3

The conversion for propane to BTU is a bit higher than for methane to BTU, because propane has three carbons. The literature value is about 2500 BTU per ft^3. Thus, 4.1 ft^3 of propane is about 10,000 BTU.

John

5.114 mol*(2220.1 kJ/mol)*(.9478 BTU/kJ) = 10,760 BTU
sorry, I saw math and couldn't resist...
*Yawn...
Great way to start the morning