Stirling engine - Wikipedia, the free encyclopedia

A Stirling engine is a closed-cycle regenerative heat engine with a gaseous working fluid. "Closed-cycle" means the working fluid, the gas which pushes on the piston, is permanently contained within the engine's system. This also categorizes it as an external heat engine which means it can be driven by any convenient source of heat. "Regenerative" refers to the use of an internal heat exchanger called a 'regenerator' which increases the engine's thermal efficiency compared to the similar but simpler hot air engine.

Noted for its high efficiency, quietness of operation and the ease with which it can utilise what would otherwise be waste heat, the Stirling engine is currently exciting much interest as the core component of domestic combined heat and power (CHP) units, the widespread adoption of which could have a significant effect upon worldwide carbon dioxide emissions[1][2]. Read More.... http://en.wikipedia.org/wiki/Stirling_engine