Stirlingengineforum.com

Thanks!

I am new to the forum and a little late to this thread by a few weeks but after reading through it I wanted to echo a couple of the other posts. Andy Ross's book "Making Stirling Engines" is available for free download (Link Below). It is an excellent read for the beginning Stirling enthusiast for keeping your goals and expectations in perspective as well as some excellent photos of his creative designs and work. On another note, it is possible for a Stirling to be dangerous under the right conditions. I remember reading about two Philips engineers who were killed when their Stirling exploded. It was a pressurized high temperature engine and vaporized lubricant had migrated into the working gas area inside the heater where it detonated. I don't think your description would fit in this category, more of a medium temperature engine, but I did want to throw that out there because we all know in the wee hours us mad scientists always want more power! Good Luck!
Andy Ross's Book Link: https://drive.google.com/file/d/0B_t-6m ... jNWQw/view

Explosions like the Philips one can only happen if oil gets in the hot chamber of an engine charged with air, and operated at too higher pressure, the oil ignites as it would in an IC engine with hot tube/bulb ignition.
Ian S C

Stainless steel welds almost like steel. It does not take a lot of extra practice, uses the same type of tungsten, and Argon gas. The one exception is that welding stainless steel requires good gas coverage. Steel is forgiving when it comes to Argon coverage. Stainless steel sometimes requires the weld to be submerged in an Argon bath or if it is an open root weld the inside of the joint must be purged with a filler gas. One of the problems of welding stainless steel is it has a tendency to warp if too much heat is applied or the pieces welded are not braced properly! Distortion can be controlled by staggering the welds and bracing the weld area frequently.

Bumpkin wrote: ↑Tue Apr 19, 2016 12:28 pm Hi Wellington. . I think this form of cogeneration is one of very few truly useful areas to invest Stirling development. Check out the electronic competition of Thermal Electric Generators first though. Cheap TEGs are becoming more available and may be getting to the point of making all of this much less relevant, like cheap photovoltaics have already done to solar Stirlings. I still think Stirling woodstove cogeneration is worth pursuing though. Some further thoughts: http://spragueriver.com/index.php/bumpkin-tech
Bumpkin

The link isn't working. I checked the internet archive, but it was never captured. Is the bumpkin-tech site still online. Has it been moved? Does anyone know?

Hi Tom. I still look in sometimes. Had to give up my paid website and I'm sorta slow getting moved to the free one. Won't have space for Bumpkin Tech anyway so I sent you a pm with the Stirling relevant stuff.
Bumpkin

Thank you!

Wow, just the kind of info I'm interested in. I also burn wood all winter and have long been interested in converting an old wood stove to power a Stirling engine and charge some batteries off-grid.

Part of the page you sent me reads : "For a wood-burning Stirling engine to run consistantly and still have a useful power stroke ratio, I would design for a heat source temperature of 250 degrees Fahrenheit, and a heat sink temperature of the nearby air at 90 degrees Fahrenheit."

Recently, having been bothered by the fact that my wood stove draft actually pulls an enormous amount of freezing cold air into the house, as well as so much heat going up the chimney, I got some dryer vent duct pipe from home Depot and duck taped it to my stove's air intake, and put the other end out through the basement window.

The stove is a forced air doubble wall wood furnace, so doesn't get very hot on the outside.

Having the stove draw it's draft air from outside directly into the firebox makes a big difference in the comfort level throughout the house. Cold air does not get drawn in from every remote corner of the home through cracks in doors, windows, electrical outlets etc. It all comes in through the dryer vent duct via the cellar window.

My point in all this being that with that arrangement, it brings the frigid outdoor winter air into proximity with the wood stove instead of a cold sink of 90F something might be rigged up to bring that down to whatever the outside temperature may be. Around here, that can often be well below freezing. Sometimes below zero.

Utilizing the draft air in this way would increase the temperature difference by 60 to 90 degrees much of the winter, but also the incoming draft would be somewhat preheated with the waste heat from the Stirling engine, which would be an additional advantage over my current arangement., As the really cold air directly into the firebox tends to reduce the heat output of the stove. Eliminating the cold draft in the house though, seems to more than compensate for the reduced heat output.

I also got one of those Magic Heat contraptions for the chimney, which helps heat the basement where the stove resides.

"Utilizing the draft air in this way would increase the temperature difference by 60 to 90 degrees much of the winter, but also the incoming draft would be somewhat preheated with the waste heat from the Stirling engine, which would be an additional advantage over my current arangement., As the really cold air directly into the firebox tends to reduce the heat output of the stove. Eliminating the cold draft in the house though, seems to more than compensate for the reduced heat output."

Yes, I agree on all points. I was just trying to keep the premise as simple as possible. In my particular case I would have to run the outside air down through the roof, which is certainly possible, but still remains on my ever-increasing "when I get around to it" list. Bumpkin