The Stirling engine

Robert Stirling patented his invention in 1816, a time dominated by steam engines. A Stirling’s engine is a heat engine that operates by cyclic compression and expansion of air or other gasses (the working fluid) at different temperatures, such that there is a net conversion of heat energy to mechanical work.

It works in closed-cycle, in this context, this means a thermodynamic system in which the working fluid is permanently contained within the system, and regenerative describes the use of a specific type of internal heat exchanger and thermal store, known as the regenerator. The inclusion of a regenerator sets the Stirling’s engine apart from other closed cycle hot air engines.  An interesting aspect of this invention is the fact that the heat can be provided by renewable energies (sun, wood…). Unfortunately the stirling’s engine was put aside because of some issues (e.g cost, long warm up time…). Nowadays it is used in some specific sectors like spatial engineering and defense.

The stirling engine : website of national museums of scotland

The stirling engine of cool energy (solar impulse foundation)