Microgen Energy Limited

Microgen Engine Corporation Holding B.v.

Stephen Charles Welty

Wayne Kenneth Aldridge

Jarlath McEntee

Christopher John Spenceley

Andrew Nicholas Hill

Roger Stuart Silcock

Christopher Mark Hardingham

Gordon Smith

Jarlath Michael McEntee

A linear-free piston Stirling machine comprising a displacer and a power piston. A rod is attached at one end to the displacer, extends through the power piston and is mounted to the casing at its opposite end via a spring. A resilient stopper at the opposite end is arranged to contact the engine casing if the displacement of the displacer exceeds a predetermined limit.

Linear free piston stirling machine

A Stirling engine () includes a reciprocating piston which drives an alternator to provide an electrical output (). The current signal () is measured by a current monitor () and a fast Fourier Transform value is produced. The FFT of the current signal () has been found to be directly related to the stability of operation of the Stirling engine. As harmonic peaks in the FFT increase, this indicates that the stroke length of the piston is approaching or exceeding a safe maximum. Correction action, such as a reduction in heat to the Stirling engine, can be taken in consequence. A variety of stroke length detectors () are also disclosed, for use in combination with, or separately from, the FFT analysis of the current signal (). Optical and mechanical switches and analogue sensors are disclosed, along with an accelerometer mounted upon the casing of the Stirling engine.

Stirling engine instability detection and prevention

Growing community of inventors

Cambridge, United Kingdom

Stephen Charles Welty