|Amazing Men and their Magical Machines||
The regenerator is an internal heat exchanger and temporary heat store which is used in the Stirling cycle engine to minimise heat wasted as the working gas moves from the heating cylinder to the cooling cylinder and vice versa. The regenerator is made out of a material which will retain some heat as the working gas moves past the regenerator. If cold gas passed the regenerator it would cool down the regenerator and heat the gas slightly. The gas would then continue to the heating cylinder and get heated. It would then return to the regenerator where it would loose some heat due to the temperature of the regenerator and it would also heat the regenerator at this point and the cycle will repeat itself. This reuse of heat in the system allows it to approach Carnot efficiency.