Abstract
A flywheel-less low temperature differential Stirling engine (LTDSE) was designed based on dynamic analysis conducted using spreadsheet programs. A prototype of the flywheel-less LTDSE was demonstrated under non-load operation of less than 30 s. Inertia moment of a flywheel did not affected, therefore the demonstrations suggested that LTDSE of which the phase angle and the distributions of balance weight are designed suitably can run without flywheel. The LTDSE was developed as a combination of two gamma-configuration LTDSEs. The phase angle between the two LTDSEs was 90°. Bellows were used instead of power pistons. In each LTDSE, the phase angle between the bellows and the displacer was 120°. Balance weights were installed in the link mechanism. The working fluid was atmospheric air. The stop after non-load operation was analyzed by the dynamic analysis program. No conventional Stirling engine analyses can explain quantitatively the reason of the stops after non-load operation. In the dynamic analysis, when the mean pressure of the working fluid in one of the LTDSEs decreased by 0.03 kPa, the flywheel-less LTDSE could not operate. During the unstable operation of the prototype, the mean pressure of the working fluid in one of the LTDSEs decreased before the prototype stopped. Although friction may have affected the demonstration of the non-load operation, the dynamic analysis suggested that tribology is not a solution. A bellows is modelled as the inner volume is affected by not only the phase but also the difference between buffer pressure and working fluid pressure.
