Stirlingengineforum.com

Hi and best regards to you all,

has anyone seen a very large stirling engine, alpha type,

with piston diameter of 600mm ( 24 inches ) or more.

if not been made yet, may I ask why ?

thank you.

aiad7

Some where on this forum is a picture, or reference to a vidio of someone (in Germany I think), who built and ran a motor using a 50gal (45gal here) oil drum as the displacer. For larger high power machines multi cylinder units are more efficient as they can run at high speed, where as the old motors with for example a speed of 100 to 200rpm, a modern motor, for power would be running at 2000rpm+, and be pressurised to a high degree. Modern materials will make all the difference. Ian S C

Ian, many times, you said "" modern materials "" , also,

"" Modern materials will make all the difference "".

What are these modern materials ?

aiad7.

Stainless steel, aluminium alloys, engineering plastics (teflon etc), hi tech ceramics. The old engines used cast iron, wrought iron, and leather for seals. The old stile engine was atmospheric, where as a high powered engine today would be pressurised, proberbly above 1000psi. Ian S C

Ian,

1000 psi. is very high pressure.

is there anything coming out of the engine.

eg. shaft ( using ball bearing ) .

how to seal the engine at this high pressure 1000 psi.

aiad7

Ian,

I know you are very ... very knowledgable in stirling engine,

and I consider you as one of the references in this FORUM.

I have found your answer, on Wed. Mar. 09 2011. 3.30am.

this was your answer:

Ian S C wrote:
"To solve the problrm of crankshaft seals; don't use them. Build the motor with a generator built in with no shaft coming out of the motor, all you need is the wires sealed, the flywheel is inside as well. Ian S C""

very long time ago, that was my idea from the beginning.

but for a large output like 1 KW,

it must be very hot for the generator inside stirling engine.

I think the wires and cables will melt inside the generator in no time at all.

don't you think it is very hot inside stirling engine.

aiad7

The Whispergen personal power station, designed , and developed in Christchurch, 40km from where I live is pressurised to (I think, can't remember exactly), 1200psi and at one time at least was using Argon gas. The generator is built into the unit, which is a 4 cylinder ALPHA motor driving through a wobble plate system. These things are being built in Spain, for sale in Europe by the tens of thousands.
It is possible to more or less seal a crankshaft, although I,v got two motors that would be pressurised if I could design a suitable seal for them, one of them is the Ross Yoke motor in my gallery, there is a plate that fits on the open side of the crankcase. Ian S C

Here's a very large stirling engine. http://youtu.be/duuk_r--lqU
I copied the information from this site's 1st page. http://www.solarheatengines.com/
It uses the phillips rolling sock seal on the power piston. With a short stroke, of course.
It appears to be a beta engine, I think. I posted the moment I found it so I wouldn't forget to.
This is the home site of the builders. http://www.sunvention.com/sv/produkte3_e.html

Technical Details from actual site:

Working Fluid: Air.
Internal Pressure: Close to atmospheric pressure. (2psi max)
Cylinder: Diameter 2 m, height 50 cm.
Temperature of hot side: 150ºC or greater. Delivered either by solar collectors at water pressure of 5 bar, or by vegetable oil at 200ºC from an EPG (see product description of EPG) or other concentrating optical systems such as Sunvention’s pneumatic fixed focus mirror.
Cooling: Simultaneous water pumping and cooling (integrated pump).
Electrical Power Output: 1.5kW
Estimated Working Lifetime: 30 years
Tested in over 1000 hours of operation, including at the Solar Test­field of Tamera, Portugal

Sunpulse Stirling engine generating electric power
technical details from non-manufacturer's site:

power piston diameter: est. 48 inches
power piston stroke: est. 2.5 inches
displacer diameter: est. 48 inches
displacer stroke: variable, est. 2.5 to 6 inches
flywheel diameter: est. 72 inches
flywheel rim: est. 0.5 inches thick by 4 inches wide
Operating RPM: est. 60 to 90
Heating and cooling pumps: est. 2 inch diameter by 3 inch stroke, double-acting
2×9.4 cubic inches per cycle = 312 grams (for water)
Operating temperatures: Hot oil or water at 5 bar pressure, 150 to 200 deg C. Water cooling, est 25 degC or higher

Estimate operating gas temperature Th=180 deg C, Tc=40 degC
Power output of generator: 1.5 kW
Engine pressure variation: +/- 0.1 bar (approximate in video of gauge)
Hot oil with possibly gravel stored in elevated barrel est. 55 gal barrel

......So......is that big enough for ya?

Hey vile_fly,

Came across that video on youtube the other day and it caught my eye, am guessing it also caught yours. I'm wondering if you or any one, may have some more comprehensive information and solid test data about the engine, other than that of the makers general claims. Have had a bit of a scour on the net but as yet, have not come up with anything that jumps out at me.

The best I've managed so far are a few long distant exposed/open shots and fuzzy cross sectional area images in some random PDF's. It would be great to get my hands on some schematics (and a million dollars and a hot model (not necessarily in that order) ). I haven't gone as far as contacting the manufacturer. Would like to know a bit more about it first. I see that it has been produced, or at least exhibited in a renewable energy type commune based in Portugal (i recall a colleague once mentioning the place).
vamoose

Thank you for sharing this!

vile_fly wrote:Here's a very large stirling engine. http://youtu.be/duuk_r--lqU
I copied the information from this site's 1st page. http://www.solarheatengines.com/
It uses the phillips rolling sock seal on the power piston. With a short stroke, of course.
It appears to be a beta engine, I think. I posted the moment I found it so I wouldn't forget to.
This is the home site of the builders. http://www.sunvention.com/sv/produkte3_e.html