Improvement of Combustion Systems in Gas Engine Equipped with Three Way Catalyst

Abstract

The gas engine equipped with three way catalyst is improved by optimization of the combustion system. In the combustion system, improvement of knocking limit is consistent with improvement of thermal efficiency of the engine. The concept of combustion optimization is that the beginning of combustion is restrained and the latter period of combustion is accelerated. Beginning of combustion restraint is achieved by flame contact with piston surface and latter period of combustion acceleration is achieved by strengther of squish flow and cancel of flame contact with piston surface. The knocking sensitivity of combustion is evaluated by Livengood-Wu integral. The intake valve close timing is optimized and knocking limit is improved by effective compression ratio reduction. Moreover expansion ratio is increased by improvement of knocking limit and thermal efficiency is improved. The small combustion chamber volume contribute the scheme of contact piston surface.