A Novel Low-Temperature Plasma Ignition System Applied to a GHP Engine

摘要

A newly developed small-sized IES (Inductive Energy Storage) circuit with a semiconductor switch at turn-off action was successfully applied to an ignition system for a SI gas engine. Additionally, a new concept ignitor using FE (Floating Electrode) which enables to construct a kind of capacitor between terminal and electrode, was developed. These mass-production-oriented IES circuit and FE plug can generate repetitive streamer discharges in nanoseconds as a low-temperature plasma. In this paper, the authors examined the mechanism to extend the lean operation limit in a gas engine. In the tested conditions, thermal efficiency with the repetitive streamer discharges was improved compared to the conventional ignition in lean conditions. NO_x emission was also slightly reduced in lean conditions.