Stirling engine facts for kids

Alpha-type Stirling engine. There are two cylinders. The expansion cylinder (red) is maintained at a high temperature while the compression cylinder (blue) is cooled. The passage between the two cylinders contains the regenerator.

A Stirling engine is a kind of heat engine that converts heat into useful mechanical energy by the movement of a piston inside a cylinder within the engine. Unlike other commonly found heat engines such as the internal combustion engine used in cars and the steam engine used on railways, it re-uses the same gas for each stroke of the piston so there is no noisy exhaust. The same gas is repeatedly heated and cooled within the engine’s cylinder.

To run it needs a supply of heat to heat its hot parts. This can come from a fire, but also from the sun’s rays, from hot rocks near a volcano or from nuclear energy. It also has cold parts which cool the gas inside it and these are kept cold by a stream of air or water flowing over them.

It was invented by a Scottish minister, Reverend Dr. Robert Stirling in 1816.

Images for kids

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  Beta-type Stirling engine. There is only one cylinder, hot at one end and cold at the other. A loose-fitting displacer shunts the air between the hot and cold ends of the cylinder. A power piston at the end of the cylinder drives the flywheel.

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  Stirling engine running.

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  Illustration from Robert Stirling's 1816 patent application of the air engine design which later came to be known as the Stirling Engine

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  A typical late nineteenth/early twentieth century water pumping engine by the Rider-Ericsson Engine Company

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  Philips MP1002CA Stirling generator of 1951

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  Point focus parabolic mirror with Stirling engine at its centre and its solar tracker at Plataforma Solar de Almería (PSA) in Spain

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  Dish Stirling from SES

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  Top view of two rotating displacer powering the horizontal piston. Regenerators and radiator removed for clarity

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  Various free-piston Stirling configurations… F. "free cylinder", G. Fluidyne, H. "double-acting" Stirling (typically 4 cylinders)

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  A pressure/volume graph of the idealized Stirling cycle

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  A modern Stirling engine and generator set with 55 kW electrical output, for combined heat and power applications

See also

In Spanish: Motor Stirling para niños