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:

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