Performance simulation by a nonlinear thermodynamic model for a Free Piston Stirling Engine with a linear generator

In the present study, an RE-1000 Free Piston Stirling Engine (FPSE) combined with a Permanent Magnet Linear Synchronous Machine (PMLSM) was analyzed. First, a nonlinear thermodynamic model of the FPSE was developed and validated. Based on this model, gas temperatures and pressures in different parts of the system and also its thermal efficiency can be calculated. Then, the PMLSM was modeled. At the next step, the systems were combined, and the results of the adapted controlled combined system were presented. Finally, by modifying the reference velocity parameters (amplitude and frequency), respecting the physical limitations of the system, it is possible to find the optimum operating point. At this optimum operating point, the efficiency of the system is maximum. The results also showed that this optimum point happened when the summation of the pistons' strokes (power piston stroke + displacer piston stoke) was at its maximum amplitude.

Automated summary

This study analyzed the combination of an RE-1000 Free Piston Stirling Engine (FPSE) and a Permanent Magnet Linear Synchronous Machine (PMLSM). A nonlinear thermodynamic model of the FPSE was developed and validated, and the PMLSM was also modeled. By modifying velocity parameters, the optimum operating point with maximum system efficiency was found.