Test results of applicative 100 W Stirling engine

A small 100 W displacer-type Stirling engine, the `Ecoboy-SCM81´ has being developed by a committee of the Japanese Society of Mechanical Engineers (JSME). The heat engine contains unique features, including an expansion cylinder which is heated by either combustion gas or direct solar energy. Also, a simple cooling system rejects heat from the working fluid. A displacer piston has both heating and cooling inner tubes for the working fluid which flows to and from outer tubes. The outer tubes for heating were located at the top of the expansion cylinder and the outer tubes for cooling were located in the middle of the cylinder. A regenerator is located in the displacer piston. The components of the engine adopted some new technologies. For instance, a porous type matrix consisting of pressed zigzag stainless steel wires was adopted for the regenerator. The matrix is practical for Stirling engines because it can be made at low cost and the assembling process is simplified