March 4th, 2008

DIY Stirling Engine

DIY Stirling Engine:
You need to a flashplayer enabled browser to view this YouTube video

The author writes:

Stirling Engine Demonstration Model. It is a do-it-yourself construction out of simple materials like test tubes, Lego pneumatic cylinders and marbles.

The starting position of the engine is tipped to the left. The alcohol burner heats the air in the right area of the test tube; the air expands and pushes the pneumatic cylinder and thus the test tube upwards. The marbles roll to the right. The hot air is then forced to the left, where it gets cooled. The cool air shrinks, the pneumatic cylinder moves downwards and the test tube tips counter clockwise. The marbles roll left and the air is pushed right, to the hot side. The air expands and moves the piston again. And so on and so forth.

There’s a piece of steel wool in the bottom of the test tube (hot side). It’s both, heat exchanger and cushion (to avoid the test tube to break). In the test tube are placed five marbles that act as displacer piston as they move the air from the hot side to the cold side and backwards. As friction is a common problem in building Stirling engines, I decided to use a low-friction “LEGO” pneumatic cylinder as working piston. Furthermore the whole system has to be 100 % leak-proof; I used an original Edradour Scotch Whisky cork to close the test tube and finally silicon to seal all crucial parts. To make the engine finally run some fine tuning in terms of balancing the test tube and positioning the pneumatic cylinder and the heat source is necessary.

DIY Stirling Engine: [Link]

Stirling Cooler and Stirling Engine

Stirling Cooler and Stirling Engine

The Stirling cycle machine, which can operate as either an engine or a heat pump, has aroused much interest because of its many favorable characteristics. These include:

  • Minimal pollution. In the case of an engine, the exhaust gases are comparatively clean and cool.
  • Silent and practically vibrationless operation in some configurations.
  • Potential for low fuel or energy consumption. The maximum attainable efficiency or COP for any heat engine operating between the same temperature differential.
  • Multi-fuel capability. The energy source may be almost of any form whatever, so long as it is available at a sufficiently high temperature. Stirling engines have been run on solar energy and a variety of liquid and solid fuels. This applies to heat pumping as well by the use of the duplex configuration.
  • In many instances, it is possible to hermetically seal the machine thus eliminating problems arising from dirt ingress. Some of these configurations have demonstrated operating lives exceeding 10 years.
  • Reversible operation allowing the same device to be used as an environmentally friendly wide temperature range refrigerator or heat pump. This feature also introduces the possibilities of regenerative braking.
  • Reasonable specific power (currently between 0.067 kW(e)/kg for higher power engines down to 0.033 kW(e)/kg for lower power engines). As a low capacity heat pump (up to a few hundred Watts), the specific lift is considerably better than other heat pump technologies (30 to 40 W/kg).
  • Favorable torque characteristics for transportation applications. This leads to simpler transmission designs.
  • Mechanical simplicity. In some configurations gas bearings are easily implemented thus avoiding the need for oil lubrication.

Stirling Cooler and Stirling Engine:


MSI usually not very well known for innovations in the Motherboard area of the market has come up with a design that i think it will sure influence other Motherboard manufacturers in the future. Because the race to more efficient and green electronics has started its just a matter of time until all motherboards will use solutions like this one. Talking about the MSI’s Stirling Engine its simple, the CPU drives its own fan. MSI’s Air Power Cooler uses the energy inherent in the expansion of air as it warms up to drive a fan. As the CPU gets hot, it causes air in a piston to expand. That pushes out the piston rod, which turns the fan rotor, pulling air over a heatpipe-fed heatsink. The heatsing helps cool the piston, so the air inside becomes more dense, pulling the piston rod back to its original position.

MSI’s Stirling Engine-based cooler (powereless) in theory

The mechanism is well known and documented as the Stirling Engine and its named after its creator, Scottish engineer Robert Stirling, who described it in 1816, though the principles on which his machine were based were uncovered in the 17th Century.

MSI’s Stirling Engine-based cooler (powereless) in practice on a motherboard

MSI’s version can transfer over 70 per cent of the heat power to motive power, the company claimed, and it doesn’t use a drop of electricity to drive the fan. It’s not totally efficient, which is why it won’t run in perpetuity, but it is kicked into motion simply by the heat generated by the chip.

MSI has built the powerless cooler and placed it on a motherboard, which it’ll demo at the CeBIT show in Hanover, next week.

© 2007-2011 YourITronics | Any logo, trademark and project represented here are property of their respective owners | Wordpress | Privacy Policy    RSS