Parametric analysis of a dual-piston type free-piston gasoline engine linear generator

The free-piston gasoline engine linear generator (FPELG) is linear type power device, which couples a linear internal combustion engine and a linear electrical generator together. Free-piston gasoline engine is commonly modeled using simplified zero-dimensional models. In this paper, parametric analysis of a dual-piston type FPELG is presented, aiming to find the piston operation characteristics and the performances of the FPELG during the generating process. Model validation was undertaken with the test data from a running prototype, which showed good agreement. The results show that with fixed stroke, lower moving mass would lead to higher indicated power. With fixed moving mass, shorter stroke would make higher indicated power. The FPELG was observed to be operated at high load, and it was prone to operate at relative low speed. The influence of combustion parameters, i.e. the ignition timing and the combustion efficiency to the FPELG engine performance were also investigated respectively.