ANALYSIS OF FREE-PISTON STIRLING ENGINE LINEAR ALTERNATOR SYSTEMS .2.RESULTS/

A coupled electric, dynamic, and thermodynamic analysis, developed by the authors for free-piston Stirling engine/linear alternator systems and reported in the first part of this study, is applied here to an ex isting and operating plant in order to satisfy the following objective s: firstly, to test its capability to predict the performance of such devices both at design and at off-design conditions, by means of a com parison with experimental results. This is very important since a high prediction capability allows the developed analysis to be used not on ly for performance evaluation, but also for design purposes, Secondly, to quantify separately the effect of the various elements that have a stabilizing influence on the system when the load is changing. In thi s way it is possible to single out those parameters that may be varied , when designing the system, in order to improve its stability. In fac t, a good stability is required when large changes of the operating co nditions are foreseen during the operation. In order to illustrate the se features, we have considered, as an example of a thermoelectric dyn amic energy conversion system, the well-known Harwell thermo-mechanica l generator, whose testing has been carried out, and the results provi ded, by Cooke-Yarborough for use by authors.